Vol. IX. No 31; 



THE AGRICULTURAL NEWS. 



250 



interesting because, like manures and water, they 

 suppl)' examples of limiting factors that are mutually 

 interdependent. 



The contemplation of these facts, like that of many 

 others connected with agriculture, serves, for one thing, 

 to bring forward the importance of proper tilhige. 

 Without water, food in the soil cannot be used: with- 

 out proper conditions in the soil, food cannot be 

 produced and liberated there; without the presence of 

 this food, the plant cannot make use of the light and air 

 by which it is surrounded. Proper tillage provides for 

 the regulation of the first two of these, so that the third 

 condition, which is always fulfilled, may be employed 

 by the plant to the best advantage. 



It will be evident, now, that the minimum extent 

 of the presence of any one of the essentials of plant life 

 causes a minimum employment of the others. This 

 explains why, often, the supplying of a single factor, to 

 its proper extent, will cause a large and significant 

 increase in the crop yielded by a plant, and why, for 

 the determination of this factor, the most successful 

 results will be obtained by a thorough and methodical 

 consideration of its requirements. 



SUGAR INDUSTRY. 



on that determination by double polarization by Clerget, so 

 that they are not included with the sucrose. Their reducing 

 power i.s less than that of an equal weight of invert sugar, 

 and as the amount of that con.stituent is exclusively ascer- 

 tained in our analyses by the weight of cuprous oxide precipi- 

 tated from l-'ehUngs solution, it i.s tlear that, although the 

 percentage of gluco.se will be found a little too high, yet the 

 great bulk of the decomposition products escape detection 

 and determination. They arc also soluble in acid alcohol, 

 and are, accordingly, not found together with the real gummy 

 matter; further, they are only partly precipitated by basic 

 lead acetate, and do not show to the full extent in the figure 

 for the gums ascertained after Peck's method. 



It is thus seen that the decomposition products are not 

 determined by the usual methods used in the analysis of 

 molasses, and that these products may be held accountable for 

 the discrepancy always met with on comparing the sum of 

 constituents determined individually with the total dry sub- 

 stance found b}' des.sieation. 



Our experiments in .separating exhausted molasses into 

 fractions by means of precipitation with alcohol showed 

 that the unknown organic body behaves just as the sugars. 

 It collects in the same fractions as sugars do, which leads 

 us to believe that it plays the .same part in the formation 

 of molasses as does the glucose from which it originates. 



At any rate, its amount is in some cases so very great 

 that it even exceeds that of the unchanged glucose, and when 

 in those mola.sses a low purity is accompanied by a very low 

 glucose content, we are convinced that thi.s is because the 

 decomposition products of the glucose have taken its place in 

 the formation of mola.s.ses, and that the sum of glucose, and 

 decomposition products of glucose which have the same 

 melassigenic power, accounts for the small amount of sucrose 

 which is combined in an uncrystallizable form in the cane 

 sugar molasses. 



PRODUCTS FROM CHANGES IN THE 



GLUCOSE IN MOLASSES. 



The most recent numbers of the International 

 Sugar Journal have contained articles, by H.C. Prinsen 

 Geerligs, on the products that are formed in molasses 

 as a result of the decompi^sition of glucose. The con- 

 clusions that are reached at the end of the investigation 

 are given in the July number of that journal, and are 

 reproduced here. 



The results of the experiments detailed seem to be that, 

 under circumstances that normally occur in cane-sugar fac- 

 tories, part of the invert sugar of the juice is broken up into 

 bodies which partly escape in a gaseous ' state, and partly 

 remain in the juices, syrups and molasses. The latter are 

 but slightly optically active, are liable to further continuous 

 decomposition, have a dark-brown coloifr, and possess an 

 unstable reducing power, which is at any rate much less than 

 that of a similar weight of invert sugar. It is not yet 

 ascertained whether any of these decomposition products are 

 fermentable, but it is certain that at least a part of them 

 may be encountered in the residuum left behind after complete 

 fermentation. 



The decomposition products are uofl-volatile, totally 

 combustible bodies, and therefore are not found when deter- 

 mining the water and ash content. Further, they have 

 a slight rotatory power, which exerts a small influence on the 

 sucrose determination by direct polarization, and none at all 



A Central Sugar Factory for Zululand.— The 



following reijort i> taken from the Produce Markets' Revievi 

 for July "2, 1910, which reproduces it from a recent number 

 of the Boiird of I'radr Journal: — 



The Imperial Trade Correspondent of Durban reports 

 that, in connexion with the alienation of Crown Lands in 

 Zululand, for the purpose of growing sugar (see Board of 

 Trade Journal of September 3, 1908, p. 489, and previous 

 notices), the Natal Government is prepared to receive 

 [iroposals from j)ersons or companies desirous of erecting 

 and working a central sugar factory at Umfolozi. There 

 are approximately 12,000 acres of land at L^mfolozi, to be 

 subdivided into farms varying from 300 to 400 acres 

 in extent, and the contracts of allotment will require that 

 from 7 A to 15 per cent, of the area of each farm shall be 

 planted with sugar-cane during the first three years, and that 

 not less than that area shall be maintained under similar 

 cultivation for a period of ninety-nine years. 



The machinery of the factory must be capable cif dealing 

 with not less than 10,000 tons of sugar in each season. The 

 scheme may provide for main tramway lines to sugar lands 

 or to the Natal Government railways, and for branch tram- 

 ways, upon terms to planters. 



The details of the scheme are left to proposers, but it is 

 suggested that terms for expropriation should be included. 



Proposals will be received by the Under Secretary for 

 Agriculture, Pietermaritzburg, up to July 31. 



