Vegetable Sugar Sources

JOURNAL OF THE INSTITUTE OF BREWING.

The following paper was read before the London Section at a meeting held at the Imperial Hotel, Russell Square, W.C., on Monday, December 8th, 1919, Mr. W. A. Kiley, Junr., in the Chair.

It was also read before the Midland Counties Section at a meeting held at the Grand Hotel, Birmingham, on Thursday, December 18th, 1919,  Mr. G. H. Burdass in the Chair.

The Extraction and Production of Sugar from Different Vegetable Sources.

By Arthur R. Ling.

1. The Carbohydrates as a Class.

The sugars, of which ordinary household sugar—the saccharose of the chemist—may be cited as a familiar example, belong to that group of compounds known as the carbohydrates, so named because their elementary composition is that of carbon combined with hydrogen and oxygen in the stoichiometric ratio in which these two elements are combined in water.

The mechanism of the formation of carbohydrates in green-leaved plants is on broad lines at all events better understood than perhaps any other physiological phenomenon in the economy of nature, whilst it involves a process of fundamental importance to the actual existence and continuance of all aerobic life.  Green plants, as regards the formation of carbohydrates, are said to be autotrophic, that is to say, they do not depend on other organisms for making these compounds, but can form them from carbon dioxide resulting from combustion and respiratory processes occurring in nature.

Now, I want you to bear in mind that the net result of the metabolic changes associated with all life is exothermic in character, that is to say, heat is evolved, not absorbed.  All organisms require heat for the production of energy and to maintain their body temperatures.  We are here concerned with aerobic or oxygen-respiring organisms.  By means of respiration, the particular organisms, whether animals or plants, are continually oxidising those portions of their tissues consisting of carbon and hydrogen to carbon dioxide and water.  Respiration is, in fact, combustion at ordinary temperature, which living organisms are able to bring about.

      Anaerobic respiration which occurs in certain tissues o£ animals and plants is probably in all cases, so far as it applies to the carbohydrates, identical with alcoholic fermentation.  The conversion of sugars into alcohol and carbon dioxide is on the whole an exothermic reaction.   As regards the production of alcohol it is a reducing reaction and ondothermic, whilst as regards the production of carbon dioxide, it is one of oxidation, and exothermic.

I have dealt up to the present with the exothermic change called respiration, which is common to all living organisms, and so far as it concerns compounds containing carbon and hydrogen consists in the production of carbon dioxide and water.  Both these well-known compounds are remarkably stable, and require the addition of an enormous quantity of energy to resolve them into their elementary constituents.  Further, carbon dioxide when present in admixture with air in any considerable quantity produces, as you know, asphyxiation when such a mixture is inhaled.

Nature has, however, provided a very simple means for its removal from the atmosphere, which not only restores the oxygon to the air, but provides plants with the carbohydrates—sugars, starch, cellulose, etc.—needed, for their development.   The green colouring matter of leaves known as chlorophyll in presence of bright sunlight is able to convert a mixture of carbon dioxide and water into carbohydrate and oxygen. Now, if we regard the carbon dioxide and water formed by respiration as derived from a carbohydrate, we shall see that this is a reversible reaction, and it can accordingly be expressed by the following equation:—

                      CHO2 + O2    ——Respiration exothermic——  CO2 + H2O

                                        ——Photosynthesis endothermic——

You will observe that the reaction, when it proceeds from left to right, is exothermic, i.e., it is attended by the evolution of heat, whilst, when it proceeds from right to left, it is endothermic, i.e., it requires the addition of heat energy.  This heat energy is furnished by the sun’s, rays.  The solar heat rendered latent, and the energy required to produce a cereal crop on a given area of land, can be calculated readily in thermal units or foot tons.  The figures cannot but surprise the layman.  In regard to the mechanism of the absorption of carbon dioxide by the green leaves of plants, 1 would refer you to the recent lecture delivered before the Chemical Society by Dr. Horaco T. Brown, in which he gives a full account of his researches on the subject with Mr. Escombe.

I have used the word photosynthesis in connection with the endothermic reaction, and this, as you will be aware, denotes synthesis by means of light.

Do not fall into the vulgar error which even now is to be found in the popular literature that animals respire oxygen, whereas green plants respire carbon dioxide.  Green plants respire oxygen just the same as animals.  Remember, as I have previously remarked, respiration is of necessity an exothermic reaction.

In the equation given above, I have used the formula CH2O as the simplest carbohydrate.  This, or rather the substance expressed by the formula H.CH:O, is formaldehyde, which has little in common with the higher members of the carbohydrate group.  There is, however, some evidence that formaldehyde, or let us call it formose, is the first product of photosynthesis in the chlorophyll cells of the green leaves.  The first visible product of photosynthesis is one of the better known sugars.  According to Brown and Morris it is saccharose.  It appears most probable, however, that the simple compound CH2O is the first actual product of photosynthesis, and that this is condensed to ordinary dextrose, levulose (CH2O)6 = C6H12O6, etc., which is translocated as such to the place of storage, the stem in the case of the sugar cane, the root in the case of the sugar beet, and the tuber in the case of the potato.

Condensations of the hexoses to saccharose and starch respectively may be graphically expressed by the following equations :—

2C6H12O6 – H2O        =        C12H22O11             2(C6H12O6)11 –  (2H2O)11       =        (C12H2O10)11

        (Dextrose)                     (Saccharose)                   (Dextrose)                 (Starch)                 

The fact that green plants acquire their carbon from carbonic acid was definitely established by Priestley in 1771, by Ingenhouse in 1779, and by Senabier in 1788.  A great advance in a quantitative sense was made by de Saussure in 1804, and by Boussingault in 1861, who showed that the volume of oxygen exhaled was equal to that of the carbon dioxide absorbed.  In 1862, Sachs observed that starch is the first visible product of this photosynthesis; whilst, as we have seen, Brown and Morris in 1893 found that the first sugar which could be identified is saccharose, and this has been confirmed by numerous other observers.  Beyer in 1870 suggested, purely ex hypothesi that formaldehyde may be the first product of the synthesis, and in this connection it may be remarked that Butlerow in 1861 had obtained in the laboratory a sugar-like substance, to which he gave the name “methylenitan,” by treating an aqueous solution of formaldehyde with certain bases.  Usher and Priestley in 1906 stated that they had detected formaldehyde as a product of photosynthesis.  They exposed green leaves, which had been killed by immersion in boiling water, to light, after which they were able to detect formaldehyde, and this observation, although criticised by some workers, has been confirmed by Schryver.

Since the view that formaldehyde is the first product of photosynthesis was first advanced as an hypothesis by Beyer, numerous workers have attacked the problem.  One of the difficulties is that since formaldehyde was known to be a protoplasmic poison, its existence, even admitting that the formation of sugars from it by a process of polymerisation occurred almost instantaneously, seemed unlikely.  Bokorny, however, showed in 1891 that spirogyra, one of the green algae, was rendered free from starch by being developed in nutritive solutions free from potassium salts and containing an excess of nitrates, carbon dioxide being rigorously excluded, the organism was killed by an aqueous solution of formaldehyde, but under the same conditions it flourished and formed starch when supplied with the compound of formaldehyde and monosodium sulphite.

From the standpoint of the physiologist it would appear that it is scarcely necessary to assume the formation of the simplest fixed statical compound such as formaldehyde, as a product of photosynthesis.  Whilst the chemist sees a difficulty in admitting the direct formation of complex substances such as saccharose and starch, to the physiologist this presents no difficulty at all, for his view is that stated by the ancients, navta pei, everything is in a state of flux.

There are more resting forms of carbohydrates than saccharose and starch, but these will serve as illustrations.  I should like to point out that dextrose and levulose (the constituents of invert sugar) and maltose (the main sugar of sweet wort), substances with which you are all familiar, are sugars possessing the group C : 0 (carbonyl) in their molecule.  In virtue of this they react with phenylhydrazine, and also reduce alkaline copper solutions.  In a physiological sense they may be regarded as dynamical compounds as distinct from the nonreducing carbohydrates cane sugar and starch, which physiologically considered are statical compounds.  I shall be told in this connection that in barley, wheat, sugar-cane, etc., there is always present a certain minute quantity of reducing sugar.  This, in my opinion, is largely fortuitous.  It may be due to the fact that the conversion of reducing sugars into saccharose or starch is a balanced reaction, or it may be due to the rupture of certain cells liberating enzymes which hydrolyse the saccharose or starch into reducing sugar.  Then the fact may he cited as opposed to my thesis that.during the ripening of fruits, the quantity of reducing sugars is continuously augmenting.  This latter case is not a true parallel, for ripening is a dynamic and not a static or resting process. Ripening, in other words, may be regarded as analogous to germination.

The metabolism of the better known carbohydrates can very well be illustrated by a study of the germination of a barley corn, and to this subject I will now direct your attention.

In its resting stage a grain of barley contains an enzyme capable of converting starch or a certain form of it into reducing sugar, but in the resting corn this enzyme remains inoperative.  As soon as germination is initiated this enzyme becomes modified, and others appear to be secreted which act on the cell walls of the endosperm containing starch granules, so that they become permeable to electrolytes and other substances besides water. Operating in vitro we know that under these circumstances we should obtain maltose as one of the products, what we obtain as initial product in situ is not known, but we may assume with a fair amount of certainty that it is some reducing sugar.  As soon as this reducing sugar is formed it is translocated through the epithelial cells to the scutellum where that quantity not taken up by the germ is stored as starch and saccharose.  The reducing sugar which is also found in germinating barley seems to consist principally of invert sugar resulting from the hydrolysis of saccharose; there is no evidence of the presence of maltose in germinating barley.  As germination continues, more cells become attacked and ultimately the reducing sugars wander or are translocated to the embryo and to the aleurone layer.  In the embryo, that portion not needed by the germ is as we have seen transformed into starch and saccharose, whilst in the aleurone layer, the reducing sugar which reaches this portion of the corn is stored as saccharose; starch is never found in the aleurone cells.  I mention these facts to illustrate to you how easily the ordinary carbohydrates with which you are all familiar are interchangeable in nature.  The problem is vastly different in the laboratory.  It was one of the great aims of the late Professor Emil Fischer to synthesise saccharose, yet this was never achieved.

As I have already pointed out, sugar is very widely disseminated in the vegetable kingdom, representing as it does in many plants the most important carbohydrate reserve substance.  Originally consumed as a condiment, or even as a medicine, it has become during the last few centuries one of the most important articles of dietary among civilized nations.  The United Kingdom, which next to the United States is the largest sugar-consuming country in the world, consumes sugar in different forms at the rate of more than 90 lb. per capita per annum.

   Sugar Cane.

The chief sources of supply of sugar are the sugar cane, Saccharum officinarum, one of the Gramineæ or grasses, and the sugar beet, Beta vulgaris.  Among other plants of less importance as sources of sugar supply may be mentioned certain species of palm, as well as the maple and the sorghum.

The earliest recorded production of sugar is from the sugar cane in India, to which country many writers believe the sugar cane to be indigenous.  Others have pointed out, however, that one kind of cane found in Java is a species, and not a variety, of the native Indian cane, so that it may have been indigenous to more than one part of the East.

In the Atharva Veda, one of the sacred books of the Hindus, mention is made of sugar cane, whilst writers at the time of Alexander the Great refer to a reed growing in India which produces honey without the aid of bees.  In the early centuries of the Christian era sugar production (from cane) was carried on in Persia and Egypt, arid at the time of the Crusades extensive sugar plantations existed in Tripoli, Mesopotamia, Palestine, Syria, etc.  In 1150 Spain had a flourishing sugar industry, and 75,000 acres of land was cultivated with sugar cane.

The Arabs and Chinese introduced the sugar cane into Tunis, Morocco, Gambia, Madagascar, Siam, Sunda Islands, the Philippines, Formosa, and Japan.  After Constantinople was taken by the Turks in 1453, much of the prosperity of the sugar industry iu the Near East and the Mediterranean came to an end.  In the fifteenth century, the Portuguese established a sugar industry in Madeira, Azores, Cape de Verde Islands, etc., whilst towards the close of the same century the Spanish commenced sugar cultivation in the Canary Islands.

After the discovery of America, the sugar cane was introduced into the various parts of the islands and mainland suitable for its production. It is stated that the sugar cane was introduced into the West Indies in 1493 on the second voyage of Columbus.  The pioneers were the Spanish, Portuguese, Dutch, and later the English and French. Sugar cane is now cultivated in the tropical and sub-tropical parts of Asia, Africa, America, and Polynesia.  In Europe, Spain is the only country which cultivates cane, and sugar to the extent of between 6,000 and 7,000 tons is now manufactured from it annually in that country.

The sugar cane is grown from cuttings, and the plant attains maturity at the end of 15—18 months, when it is cut and dealt with in the factory.  The stubble is left in the ground, and ultimately produces. shoots, called ratoons.  These are in turn cut, and produce second ratoons, and so on.  The ratoon crop is not so rich in sugar as the original cane.  However, fresh cuttings are only planted in periods of from 2—7 or more years, according to the richness of the soil.

There are places in the world in which no fresh cuttings have been planted for more than 50 years, the crop depending entirely on ratooning.  These are instances in which virgin oil exists, and are few and far between.

Much work is now being done in attempting to improve the cane by growing it from seeds produced by cross fertilising different varieties.  Here difficulties are encountered, for some varieties do not flower at all, whilst in others the pollen of the anthers is found to be infertile.

However, success has attended these experiments in different parts of the world, and it has been found possible in many instances to breed cane suitable to a given locality.

The sugar cane, as now cultivated, under the most favourable conditions, gives a crop of 30—40 tons per acre, and sometimes more, and has a sugar-content of 11—16 per cent.  Taking a yield of cane of 35 tons per acre, and an extraction of sugar of 12 per cent, this would mean a production of sugar of 4*2 tons per acre.  We have heard of as much as 7 ½ tons per acre having been obtained in isolated instances.

                                             Sugar Beet.

The history of beetroot sugar dates from 1747, when Marggraf, a German chemist, demonstrated the possibility of extracting sugar from beet.  Some 50 years later a Frenchman, named Archard, who was a refugee in Germany, continued this work, and at the commencement of the nineteenth century the first beet sugar factory was started in Silesia.  It had n capacity for dealing with about 500 tons of roots per annum, which might have produced 25—30 tons of sugar.  The industry was fostered by Napoleon the First, who thought thereby to cripple England’s colonial sugar trade.  In 1811 he ordered 80,000 acres to be planted with beet.  The industry flagged somewhat after the wars, but it was taken up by Germany as well as by France, and in 1860 the production of beet sugar was 250,000 tons.  In 1871, France produced 284,000 tons and Germany 180,000 tons of sugar, whilst in 1884 the Gorman production reached 1,000,000 tons, whilst the French production had dropped to 265,000 tons.

Coming to more recent times, in 1913, the world’s production of beetroot sugar was 8,758.900 tons, or 46*96 percent, of the total sugar production from cane and beet together.  Of this, Germany produced 2,718,000 tons.  The cane production at the same time was 9,894,200 tons.  The remarkable success met with in Germany in improving the sugar-content of the roots by selection and manuring may be judged by the fact that at the commencement of the industry the roots probably contained not more than 6 —8 per cent, of sugar, whilst the sugar content had steadily improved until the roots of the 1909 harvest contained an average of 17*63 per cent, of sugar.  Of this over 90 per cent, would be secured by modern methods.

It will be seen that the sugar-content of beets is higher than that of cane, but the crop is a lighter one.  On an average under the best conditions, about 12 tons of beets can be grown to the acre, so that the yield of sugar seldom reaches 2 tons per acre, and is generally a little below it.

The late Mr. George Martineau in his booklet Sugar: Cane and Beet, p. 17, makes the following pertinent remarks on the comparative yields of sugar from cane and beet :— “It is curious to think that this humble root” (the beet) “weighing only 2 1b. should now be giving to the world as much sugar every year as the lordly sugar cane, and that the beetroot factory should actually extract a greater percentage of sugar from the little root than the cane factory wins from the rich cane.  But it must not be forgotten that, under favourable conditions, the cane can produce twice as much sugar to the acre as the beetroot. Which will win the race?”

The British Empire, according to the last returns, had about 3,500,000 acres under sugar, mostly cane, yet the total production from this was less than that of Germany and Austria-Hungary combined, which countries could not have had so much as half that number of acres under beet.  Obviously, in view of what has been stated as to the potentialities of sugar production from cane and beet respectively, there must be something wrong with our methods.

Let us bear in mind that the British Empire exceeds all other States in the production of sugar, and the United Kingdom occupies the second place, coming next to the United States, as an importer of sugar.  It is of particular significance in connection with this last named fact that prior to the war more than 96 per cent, of the sugar imported into the United Kingdom came from foreign countries, and by far the greater portion of the imported sugar (80 per cent) was European beet sugar.   In fact, before the war the importation of raw cane sugar was restricted to the demands of those industries like brewing which found raw beet sugar unsuitable for their requirements.

As regards the consumption of sugar per capita per annum of the important countries before the war, the United Kingdom comes first with 95 lb. whilst the United States is second on the list with 89 lb., Germany 49 lb., and France 48 1b.

Following the outbreak of hostilities the production of sugar from beet had dropped from 47 per cent, to 29 per cent, of the world’s total supply.  On the other hand, the production of the British Empire had increased 3,275,500 tons in 1913—14 to 4,394,100 tons in 1917—18 (or 34*1 per cent.), whilst the total production of sugar throughout the world, which was 18,653,100 tons in 1913—14, was in 1917—18 17,556,400 tons.  The countries showing the largest increases are India, Cuba, and Java.

There is no doubt that the importance of the race now being run is fully recognised in all parts of the British Empire, and the granting of Imperial Preference should help our sugar Industry, but it must not be forgotten that all such measures without efforts on the technical side will be unavailing.  It is well to insist on this point and to indicate where, and in what directions, reforms and improvements are most needed.  Let us not forget, however, that time presses.  Our late enemies are eagerly watching all we are doing, and unless we make the necessary improvements within the next year or two we shall again be left behind in the race for supremacy.

                              Extraction of Sugar from Cane.

The extraction of sugar from cane is a matter involving very heavy crushing mills, the diffusion process which has been so successful in the case of sugar beet having largely failed when applied to cane.  Originally these mills were of a primitive type, driven by horse or other animal power, and this method still obtains in India, which up to quite recently has been the largest sugar producing country in the world.

The fact, however, that India was the largest sugar producing country in the world needs some qualification, for the sugar there produced is not of the same type as that to which we are here accustomed.  Not only is the crushing done by such primitive means that something like half the percentage of sugar is left in the canes, but the juice when obtained is evaporated in open pans, whereby another considerable portion of the sugar is destroyed.  It should be mentioned that the fuel employed for evaporating the juice consists of extracted cane or bagasse as it is called.  The native produces what he calls gur or jaggery, a soft sugar containing, in addition to cane sugar a considerable proportion of invert sugar, and in some cases much colouring matter.  All this is due to the primitive methods of extraction and manufacture adopted.  Besides this, cane grown by the natives is for the most part confined to the temperate districts of Northern India, and is practically a wild species, the canes themselves being about the size of an ordinary pencil, and the sugar-content very low.  I may mention that a Government Commission is now inquiring into the whole sugar position in India, with a view of ascertaining whether it is possible to acclimatise varieties of cane giving larger yields of sugar, more especially in tropical India, and in this connection I may mention that much valuable work has been done by Dr. C. A. Barber.  The Commission will also deal with the possibility of establishing central factories, whereby white solid sugar can be manufactured, and India converted into an exporting instead of an importing country.  Before the war, practically the whole of the jaggery made by the natives was consumed by them, whilst for the needs of the white population, some 800,000 tons of sugar, mostly European, was imported.

The modern cane sugar mill is a very heavy piece of plant, consisting of three, four, and in some cases a much larger number of rolls, to actuate which much expenditure of power is required.

The extracted juice is let into a vacuum apparatus, and evaporated until it commences to grain.  For a thin solution, such as raw juice, it has been found economical, to employ what is called a multiple effect evaporator, that is to say, an apparatus consisting of several members in which the steam escaping from one is made to boil the juice in the next vessel, and so on until the necessary concentration is reached.  After the juice has reached the point at which it grains, it is discharged from the last member of the series into a centrifugal machine, where the syrup is removed from it, and the latter is boiled for a second and sometimes a third crop, the residual syrup, which can no longer be made to crystallise, being molasses.

                                 Extraction of Sugar from Beet.

In the early days of the manufacture of sugar from beet, the extraction of the juice was accomplished by submitting the rasped roots to hydraulic pressure.  At present, however, it is carried out by a process of lixiviation known as diffusion.  The roots are first cut into slices and are conveyed by a travelling band to a series of 10—14 cells.  Hot water at about 190° F. is then introduced at the bottom of the cell so that it travels up and rises through the mass of slices.  The solution thus obtained passes over into the next cell, and so on through the whole series until the slices are extracted.

The next operation is to treat the juice with lime in order to remove certain impurities from it.  The lime is then precipitated by passing in a current of carbon dioxide in so-called saturation tanks until its alkalinity is about 0*1 per cent., calculated as calcium oxide.  If the saturation is carried further than this then some of the non-sugar substances redissolve.  The calcium carbonate and scums are then filtered through a press, after which the filtered juice is submitted to a second treatment with carbon dioxide and sometimes to a third treatment in this case with sulphur dioxide.  The final alkalinity of the juice is then reduced to 0*01 to 0*04 per cent., calculated as calcium oxide.  The juice is then let into the multiple effect apparatus and evaporated to the graining or crystallising point.  Usually first and second product sugars and molasses are produced.  The first products polarise from 95—98 per cent., and the second products from say, 87—94 per cent.  These limits cannot be strictly fixed.  Beet molasses is very constant in composition, consisting of just below 50 per cent, of sugar, 10 per cent, of ash, the remainder being organic non-sugar matters.  By suitably washing the first products in a centrifugal machine, beet crystals polarising over 99*8 per cent, can be obtained.

Sugar cane and sugar beet are thus the two chief sources of sugar in the world’s supply. There are, however, certain species of palm from which sugar is extracted. In India some of these palms yield as much as 3 tons of jaggery sugar to the acre.  Palm sugar is, however, never likely to develop beyond the limits at which it stands at the present time, for it must not be forgotten that it requires 20 years before a palm tree attains maturity.  A certain amount of sugar is obtained in America from maple, but on account of its cost this is to be regarded as a sweetmeat rather than as an ordinary article of consumption.

The phase of the sugar question of the greatest importance to us in the British Empire is whether we can by any means render ourselves self-supporting.  I am Chairman of a Committee formed by the Society of Chemical Industry known as the Empire Sugar Supply (Technical) Committee, and that Committee has drawn up a report indicating the position of the whole situation.  In the first place, we have discussed the possibilities of establishing a beet sugar industry in this country.  The experiments of Dr. G. Schack-Sommer, from 1889—1895, were the first to prove that sugar beet equal in sugar-content and purity to the best obtained at that time on the Continent could be grown in the United Kingdom.  Further, from several hundreds of analyses I have made during the last 10 years of beets grown in different parts of the United Kingdom, I have come to the conclusion that sugar beets can be grown in this country having a sugar-content and purity as high as those produced on the Continent.  The industry, however, requires an enormous amount of agricultural attention, and necessitates much agricultural labour.  Deep ploughing is necessary, in order that the crowns of the roots may not protrude above the surface of the soil, and continual earthing up is necessary for the same reason.  Sugar beet is a selected variety of the mangold wurzel, but the two are grown for entirely different objects—the sugar beet for sugar production, and the mangold wurzel as a more or less complete cattle food.  Farmers have often stated that they can obtain as much as 40 tons to the acre of mangold wurzels, whereas they can only get something like 12—15 tons of sugar beet.  Mangold wurzels are grown in such a way that they contain something like 3—5 per cent, of sugar, whilst the purity of the juice, that is to say to percentage of sugar, in the total soluble matter is something like 55—60 per cent.  In view of the purpose for which it is grown, the mangold wurzel docs not need so much attention as the sugar beet in its cultivation.  The final roots contain a much larger quantity of substances other than sugar, which they derive from the soil.  The roots are allowed to protrude above the surface of -the soil, and usually this causes the crowns to become green.  It is quite otherwise with the sugar beet, in which the object is to increase the amount of sugar produced to its maximum, and to keep other substances down to a minimum.  It is not possible for me to traverse the whole of the pros and cons of this question on the present occasion.  Much as I should like to see a beet sugar industry established in this country, I quite endorse the views of Mr. J. W. Macdonald that the establishment of such an industry would make another heavy call upon our coal, of which, as you are aware, there is such a need of conserving.  It is only right to add, however, that the cultivation of sugar beet as a rotation crop does improve the soil for cereals and other crops, mainly on account of the deep tilth which it necessitates.  On the other hand, there are so many parts of the British Empire, India, West Africa, the West Indies, and numerous other totally undeveloped colonies, where cane could be cultivated and a sugar industry established.  In the case of cane, as I have already stated, not only is the yield per acre of sugar twice or even more than that which is obtained from beet, but it affords its own fuel.  When we look at our vast Empire and the possibilities it has of growing cane, we should, I think, make every endeavour to increase the production of sugar from that source within our Empire rather than purchase as we did before the war in this country, over 80 per cent, of the total sugar we consumed from Germany and other Continental countries.

So far as the brewing industry is concerned we have to remember that beet sugar is of very little significance.  Raw beet sugar cannot be used as it is well known to produce troubles, and refined beet sugar is not suitable because it does not communicate to the beers that luscious flavour which is obtained from raw cane.  Consequently the brewer’s interest in the sugar question becomes essentially one of increasing the production of cane rather than of beet.  I should like to point out in connection with the use of sugar in brewing that raw cane sugars are very liable to be contaminated with bacteria.  Hence when they are employed in the brewery the greatest care should be taken that their solutions are sterilised by proper boiling.  Possibly in time this may be overcome, since in some of the sugar plantations where scientific methods of extraction have been introduced the liming of the juice is carried out, so that in these cases there is less chance of bacterial contamination of the raw sugar, in addition to which a cleaner product is obtained.  As things stand at the present time, there can be no doubt that the use of refined sugars such as the majority of brewers employ is perfectly justified.

I should like, in conclusion to express my thanks to Mr. A. G. Eastick for the loan of lantern slides from his very complete collection.

                              Discussion at London Section.

The President (Mr. S. O. Nevile) said that he thought every practical brewer was primarily interested in the sugar he obtained in the mash-tub.  On the other hand, nearly all of them relied to a considerable extent on the adjunct cane-sugar; and consequently Mr. Ling’s paper dealing with that particular part of the subject was of great interest.  They had with them that evening Mr. William Martineau, who be thought was the originator, or at any rate a moving spirit, in an association called the British Empire Sugar Research Association.  He felt sure that they would be interested indeed if Mr. Martineau would tell them something of what that research association proposed to do.  He would like to ask if that body were associated with the committee in which Mr. Ling had said he was interested.  That research association might have some bearing on their own research scheme at the Institute of Brewing; sugar being so important a matter it might well prove that to some extent they might work together, perhaps not so much in encouraging the production of sugar, but possibly in the development and improvement of the methods by which it was prepared for brewing.

Mr. William Martineau said that he was very glad of the opportunity of saying a word about sugar research, because he hoped brewers, as large users of sugar, were interested in the matter and would eventually become still more interested.  Referring to Mr. Ling’s Committee of the Society of Chemical Industry, as that committee and the sugar research committee were both doing work of the same kind, with the same object, it had been decided that these two committees should link up together, rather than over-lap in their work.  He agreed with Mr. Ling that the British Empire should aim at being self-supporting in sugar; he hoped that we should never again see German beet sugar in this country.  With this object in view, some three years ago, a meeting was called together of leading people representing various branches of the Sugar Industry all over the Empire.  That committee finally became a very important organisation, known as the British Empire Producers’ Organisation.  The sugar section of that organisation worked very hard to try and get the Government to recognise that the Empire could produce all the sugar required for the Empire, if the Government would-only give them a little help to start with.  In other words, they were out for colonial preference.  As is known, colonial preference has now been granted, which should be a great help to the cane-sugar growing colonies, and with this assistance, if cane planters set to work in the right way, there was no doubt England would be quite well able to do without German sugar in the future.  The Germans had made a great success of beet sugar, because they had gone in for research; it was therefore important that cane-sugar producing parts of the Empire should take up research, and bring their machinery, methods and processes right up to date.  With the object of starting a comprehensive scheme of sugar research, rather more than 12 months ago; a provisional committee was formed, representing not only planters, but every branch of the Sugar Industry within the Empire, and with the support of the Government Department of Industrial and Scientific, Research, the British Empire Sugar Research Association came into being, and was registered at the end of July of this year.  This Association was now governed by a council representing sugar planters, sugar refiners, and sugar users of every kind, including brewers, the Brewers’ Society being represented on the Council by Mr. F. P. Whitbread and Mr. Graham Aldous.  The aim of the Association was to establish, in co-operation with the Government Department, an Empire scheme for the scientific investigation of the problems arising in the Sugar Industry, and to encourage and improve the technical education of persons who were, or might be, engaged in the industry.  By so doing it was hoped vastly to increase the production of cane-sugar within the Empire, which would be to the great advantage of all industries which used sugar as a raw material.  He hoped that the Brewing Industry would favour this scheme with their practical support.  A prospectus had been sent out to every brewing firm in the country, and he hoped head brewers and chemists would study that prospectus, and not only become members themselves, but advise their firms to support the scheme in as substantial a manner as possible.

Captain H. L. HlND said that he had always been very much interested in the Beet Sugar Industry; and wished to know how it was proposed to overcome the difficulties of transport in England where the railways were already overburdened.  He had seen the supplies of the Army in France held up or delayed when the Beet Campaign started in the autumn.  Trucks could not be obtained as they were wanted for the beet.  How was that going to be got over in England?  He thought it would prove to be one of the greatest obstacles to the setting up of the industry, as there were so many trucks wanted in such a short time just when the harvest came.  Mr. Ling had shown on the screen Char filters.  He had had the opportunity of seeing a few sugar factories, but they were not using Char filters, and he was told that the latter were quite antiquated.

Dr. G. Schack Sommer said that he was very much in favour of the introduction of sugar beet into this country.  Although he believed the cost of making cane [sugar was much lower than that of making beet sugar, due to the fact, to which Mr. Ling drew attention, that the cane bagasse supplied the fuel for manufacturing the cane sugar, whereas beet sugar manufacturers had to rely on coal or other bought fuel, the advantages of introducing beetroot sugar into this country would be appreciated by farmers, because, as the sugar beet required intensive cultivation, they would increase their crops to such an extent that the land which.they planted with beet would not be missed.  Continental experience had demonstrated conclusively that beetroot sugar was not an exhaustive crop; on the contrary, it increased the fertility of the soil if a proper rotation of crops was observed.  Wherever sugar beet was introduced crops of wheat and other corn crops were so much increased that the beet was simply an extra crop, and thus an extra income to the farmer. Further, the beetroot gave employment to men in the country at a time of the year when there was no work for them to do, so that they could keep very much larger armies of working men in the country than now, because usually they had no work for them in the winter.  Again, when the sugar had been extracted from the beet, there was pulp left which would feed the cow? or any other animals.  In that way many more cattle could be kept on the same farm than could be done without the sugar beet crop.  He thought that those things went a long way in favour of recommending the introduction of the sugar beet industry.

The Chairman said that he felt they were all very much indebted to Mr. Ling for his paper.  He thought that they were up against the farmer in this country who was against growing beet.  In his part of the country they had had some experience.  The farmer could not understand why, when he sent a truck of beet to the factory, if he sent 10 tons to the railway station he was only allowed, say, 8 tons pure beet.  That had been the cause of all the trouble in growing beet.  The farmer would not take the factory figures.  As they knew, when the beet came into the factory they took about two skipfulls out of each truck which went into the laboratory, was washed, and the dirt taken away.  From that amount of dirt in the two skips the amount of dirt in the trucks was calculated.  The fanner would not take that for granted, but wanted to see the condition himself.  Another great trouble was the question of labour.  There was a lot of imported labour in Norfolk from Holland, Germany and Austria; and he believed that imported labour put up the backs of the farmers and the local labour.  The local labour would not take their instructions from these Continental men.  He thought, unless they educated the farmer and the labourer, beet sugar would not be much good in this country.  Those who had been in Germany and had seen the beet seed storehouses, knew the enormous care: that was taken to select the seeds.  If they could do all those things with beet sugar, why could not the Empire produce more cane sugar?  He believed 99 per cent, of the machinery used in the cane factories abroad came from Scotland.  He could not understand why that was so, and at the same time they were producing less cane sugar in the Empire.  He had used English beet sugar in mineral waters.  Whether it was properly refined or not he did not know, but he had found it gave a sort of ropiness.

Mr. Ling (in reply) said that he had not gone into detail.  He was afraid he had misled many of them by showing the charcoal cistern and not properly explaining in what connection he showed it.  On the Continent, for some years past the first runnings sugars were the ordinary white beet crystals which were only of a slight brownish colour and polarised at 99*5 per cent, with 0*1 per cent, of ash or less, and no char whatever was used in their production.  The massecuite was simply washed in the centrifugal.  He quite agreed with Dr. Schack-Sommer that if the beet sugar industry were introduced into this country it would be of very great help to agriculture; but at the same time they had great difficulty to persuade the farmer of those things.  First of all the farmer told them that he could get 40 tons of mangolds per acre, whereas he only got some 15 tons or less of beet.  He also did not take kindly to the exhausted slices.  If the industry were worked on a co-operative system as they did on the Continent, giving the farmer an interest in the sugar factory, and the sugar manufacturer an interest in the farm, he had no doubt they would be able to get together some sort of beet sugar industry in this country.  With regard to transport he agreed with Captain Hind that that was a difficulty; but he looked forward to the industry being established in such localities as commanded transport by canal.  He thought they had a sufficiency of canals; but he did not believe that the sugar industry would ever assume very large proportions in this country.  But if beets could be grown and factories established with command of canals, and the beet distributed by water to different centres, he thought they would get over the difficulty of transport to a great extent.  Dealing with what the Chairman had said as to ropiness, the sugar which was turned out in cane sugar factories was raw sugar, often contaminated with organisms which refining removed, and therefore there was always the danger of ropiness.  The ropy organism of sugar, leuconostoc mesenteroides, was far more prevalent in beet sugar than in cane sugar.   When he had been analysing beetroots, he hail always found if he took a little earth away from the root and put it into beet juice which was sterilised, he could get a fair growth of leuconostoc mesenteroides by the next morning.  Beet juice seemed to be a particularly suitable medium for its cultivation, much more so than cane juice.

(A vote of thanks to the Author was passed unanimously).

                     Discussion at the Midland Counties Section.

The Chairman (Mr. G. R. Burdass) said that it seemed to him that cane produced twice the quantity to the acre as compared with beet.  If they were to keep up their name as the producers of the greatest portion of sugar, they ought to encourage their Colonies in every possible way by giving them more up-to-date machinery and encourage them to produce the sugar required.  Some small experiments had been made in the production of beet sugar, but he did not know of any instance where the fanner had thought (it to continue the production of beet; presumably, he had not found that it paid him so well as mangold wurzels, and, in view of the comparatively small acreage of the British Isles, he thought their land should be devoted to the production of food-stuffs; to a great extent, they could do without sugar more easily than they could do without cereals.  He did not think that there would ever be a large beet sugar industry in Great Britain, and if anything warranted their promoting sugar growing, he thought it should be done in the direction of encouraging the Colonies, where sugar could be so much more easily grown.

Mr. John M. Lones said that he had been particularly interested in the early portion of the paper dealing with the synthetic formation of sugar in plant life; in other words, nature’s efforts to manufacture our sugars.  It carried his mind back many years to a paper read by the late Dr. Sykes—an old friend of Mr. Ling’s—wherein he described the development and formation of starch in the barley corn on similar lines to those adopted by Mr. Ling to-night.  That paper was written in his early days, but he always remembered the interest he had at the time in Dr. Sykes’s attempt to unlock nature’s secrets.  When they realised the immense tracks of land within the British Empire suitable for cultivation of either cane or beet, it reflected no credit upon their commercial enterprise to learn that, prior to the war, 96 per cent, of our sugar was imported from various countries, and of this total 80 per cent, was sent to them by European countries.  For obvious reasons, this high percentage had been reduced since 1914, but from past experience they must recognise that if this matter were not taken up by this country with sufficient energy and thoroughness, what they still called “enemy countries” would strive to restore their former rate of production in the hope of making Great Britain again dependent on them.  The Empire Sugar Supply Committee, with Mr. Ling as its Chairman, was working hard to check this tendency, and in doing so both he and his colleagues were performing, in the truest sense of the word, work of the highest national importance in attempting to make the Empire self-supporting regarding its sugar supplies.  They were deserving of the strongest encouragement and support which could be given them, for their work, like all big undertakings, was crowded with difficulties. Mr. Ling had stated to-night, and had published the same evidence on more than one occasion, that this country could grow sugar beet equal in sugar-content and purity to that grown on the Continent, which made it the more disappointing to have to admit that so far the production of beet sugar had not met with the success it deserved here, chiefly owing to the want of technical knowledge on the part of the agriculturist, the absence of organised co-operation between farmer and factory, and meagre support from the Government.  The report of Mr. Ling’s Committee showed that between the total quantity of sugar produced throughout the Empire and the total consumed, there was a deficiency of 2 ½ million tons.  This was serious and evidently under the most favourable conditions would take some years to make good.  The conditions to-day were not favourable, there was a general scarcity of labour, new plant was costly, the investors required coaxing with ample security before parting with their money.  Mr. Ling was evidently casting longing eyes upon India to increase the Empire’s supply of sugar, and it was possible by improved methods of cultivation and recovery of the sugar and by making fuller and better use of Gur, a substantial increase might be effected, and it was to be hoped that in India, as well as in other parts of the Empire, something would be done in that direction.  Mr. Ling had referred to Spain as the only European country growing cane, and having in mind the very serious shortage and the improbability of it being made good within the Empire within a reasonable time, caused one to inquire if efforts could not be made to induce a friendly nation like Spain to increase her cultivation of cane.  She was comparatively near to us, and being protected from cold winds on the north by the Pyrenees, and having the benefit of the warm winds from the Mediterranean, her climate was a most favourable one.  A fertile well-watered country with the sea washing three sides of its borders, her position gave her such natural advantages, that surely something could be done to encourage her to increase the world’s sugar crop.

Mr. R. H. Hopkins said that they had been reading a lot lately in the local Press about brewers and farmers.  He suggested that now, indirectly, the brewer had a fresh grievance against the farmer who declined to produce beet and preferred to grow mangold wurzels.  If the farmer would grow sugar beet, that might keep out the German beet sugar; the domestic consumer could then have our beet sugar, allowing the brewer to use cane sugar.  He would like to ask Mr. Ling if he personally believed in the synthesis of cane sugar supposed to have been effected by the Russian chemist Marchlewski in 1899.  This was effected by the condensation of potassium fructosate with chloracetyl-glucose.  He believed that many chemists agreed that it was not a genuine synthesis.  It was evident that a difference of opinion existed on the matter.  He would like to know Mr. Ling’s views on the subject.

Mr. W. Scott said that he had had some experience of sugar growing in the West Indies just about the time the German sugar bounty was killing the trade out there.  Many planters gave up sugar planting in consequence, and devoted their land to planting cocoa, coffee, and other things, and no doubt at the present time the particular island in which he lived was practically doing nothing in the way of sugar growing.  Mr. Ling had put on the screen some slides of very crude plant.  He (the speaker) thought that in the factory he was connected with the plant was equally crude.  They had a water-wheel and a three-roller mill, and had to carry the canes to the mill in bullock carts.  Because of the poor price obtained for sugar when shipped to England many of the planters did not trouble to crystalise out their sugar but sold it in the form of syrup for which there was a ready sale amongst the natives.  Without better organisation it would be difficult for small planters of cane to hold their own against the well-organised beet industry, and it was pleasing to note from the paper that this matter was receiving the attention of the Government.

Mr. Ling, replying to the discussion, thanked the meeting for their kind reception of his paper.  He had brought with him a good deal of statistical matter, but he found that the shortness of time made it quite impossible to deal with it.  “With regard to the question of beet-growing, it had been suggested that the land should be used in England for the production of other foods and foodstuffs rather than beet, but the beet crop was one to which Germany owed not only its sugar industry, but, to a large extent, its agricultural industry, because no crop opened up the land so thoroughly as the beet crop.  Beet required deep cultivation, very much deeper than English farmers were inclined to carry through, and their efforts at producing beet had been carried out under the worst possible conditions.  On the other hand, where that deep cultivation had been given, the roots in this country was equal in every respect to those grown on the Continent.  Mr. Lones had pointed out that there were vast tracts of land in the British Empire which should be put under super cultivation for the growth of sugar.  That was quite true.  The object of getting all those statistics together, and the preparation of a report by the Special Committee, had in view the filling up of that gap.  The statistics showed that as an empire they were 2,500,000 tons in production below their consumption.  Mr. Lones said that sugar should be grown in Spain.  There was a good deal to be said for that, but Spain was not the British Empire, and the object of himself and his committee was to get the sugar grown within the Empire.  India was a long way off, and he was afraid it would take years for the effort to produce Indian sugar to materialise.  There were, however, on the West Coast of Africa vast tracts of land very suitable for sugar-growing, and that work ought to be taken up.  Egypt, also, used to be a sugar-producing country to a greater extent that it was at present, and steps were already being taken to increase sugar-growing there.  The West Indies, however, had great possibilities, and, if cultivated to the fullest extent, would do something towards making up the deficiency, though they could not do everything.  Mr. Scott had told the story of the way in which the sugar bounties killed the West Indian industry.  He (the speaker) knew quite well that that was the case.  At the time when he (the speaker) served on that Committee, Sir Francis Watts, the Imperial Commissioner of Agriculture for the West Indies, was in this country, and he agreed that the industry would have died altogether if timely aid had not been given.  He quite agreed with Mr. Allcock that there ought to be a sugar industry in this country.  The great essential was to get co-operation between the farmer and the sugar manufacturer, and until they got that they would never have a sugar industry.  Whilst in no way opposing the establishment of a beet sugar industry in this country, he would point out that the main question was that in the Colonial Empire they could get at least twice as much sugar per acre from cane as they could from beet.  That was a matter well worth consideration.  With regard to the scientific question that had been put, he was quite aware of the experiments of Dr. Marchlewski, who claimed to have synthesised cane sugar, but he had forgotten what the conditions were, and the experiment was discredited by many people since it had not been found possible to repeat it.  But although a chemist could not repeat experiments it did not follow that the original chemist was wrong, because it was often difficult to reproduce the conditions.

                                        BIBLIOGRAPHY.

Noel Deerr, ‘Cane Sugar’ 1911.

R. N. Dowling, National Sugar Beet Association  ‘Preliminary Report on Trials and Experiments on the Cultivation and Manuring of Sugar Beet.’

H. C. Prinson Geerlings, ‘The World’s Cane Sugar Industry’, 1912.

‘Home Counties’ (J. W. Robertson-Scott)  ‘Sugar Beet.’

G. Martineau, C.B.,’ Sugar, Cane and Beet—An Object Lesson.’

G. Martincau, C.B., ‘ A Short History of Sugar, 1850—1916’

‘Agricultural Journal of India.’ Papers by H. E. Annett, C. A, Barber, Wynne Sayer, etc.

Bulletins of the Agricultural Research Station, Pusa. Papers by P. Abel, H. E. Anuett, 8. C. Banerjee, C. A. Barber, J. H. Barnes, G. Clarke, Khan Bahadur S. M. Hadi, W. Hulrao, Nuib Hussain, Syed Zamin Hussain, Wynne Sayer, Lakshuii Shanker, G-. Somers Taylor, etc.

Memoirs of tho Department of. Agriculture in India. Papers by H. E. Annett, C. A. Barber, G. K. Lele, Rhailal M. Amin, etc.

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Bulletin of the United States Department of Agriculture, No. 473.

International Sugar Journal.

Mauritius Almanac, 1918.

‘Queensland Sugar Industry’ 1913.

‘Sugar Cane in South Africa’ 1913.

‘Sugar Beet Industry of Canada’ 1909.

‘Sugar Beets’  by C. A. Zacitz and A. W. Mason, Ontario Agricultural College, West India Committee Circular.

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