26 



T H !•: CUBA REVIEW 



SUCROSE AND POTASH IN CANE JUICE 



Tlie Iiilcniatioital Sugar Joiinuil for 

 August, .1911, contains a paper by li. C. 

 Prinsen Geerligs, which is of much inter- 

 est, as it demonstrates the existence of a 

 relation between the sugar in the juice of 

 the cane and its content of potash. 



Tt is first pointed out that the observa- 

 tion has been made several times to the 

 effect that, although the quantity of ex- 

 hausted molasses obtainable from a given 

 variety of cane varies considerably, yet the 

 composition of the molasses, and especially 

 the amount of potash in it, does not differ 

 much, from sample to sample. Cane juice 

 of a high purity gives exhausted molasses 

 very similar in its composition to that from 

 juice with a very low purity. 



Further, analysis makes it evident that 

 the ratio of potash to dry substance in ex- 

 hausted molasses varies little, although the 

 quantity of molasses obtainable exhibits 

 considerable differences. For example, in 

 the case of juice of 7.") purity yielding 

 2^:1 times the quantity of molasses which 

 is produced by juice of 90 purity, the 

 potash content of the latter is by no means 

 2^/i> times that of the former; and this is 

 only what may be expected if both had 

 contained at the outset the same ratio of 

 potash to dry substance content. As, how- 

 ever, this potash content does not differ, 

 we are compelled to admit the fact that, 

 generally, a cane juice of low purity is 

 more charged with potash salts than a 

 juice having a high quotient of purity. 

 This, combined with the fact that the pu- 

 rity is influenced mainly by the glucose 

 content, leads to the conclusion that the glu- 

 cose in a ripe cane is accompanied by a fixed 

 proportion of potash salts, so that the 

 latter keep back in the cane juice a quan- 

 tity of glucose which does not disappear 

 during the ripening of the cane, and thus 

 the quotient of purity is lowered. If the 

 potash salts possess such an action, a ripe 

 sugar cane with a high potash content 

 must contain a high percentage of glucose. 

 Actual investigations have shown this to 

 be true in the case of the beet. 



The matter is complicated by the fact 

 that differences in purity are brought about 

 by the soil conditions, cHmate, the manures 

 employed and the variety of cane ; the 

 degree of maturity of the cane also entails 

 differences which are likely to cause con- 



fusion. The work of the author, ombined 

 with the results of others, shows that there 

 is no preceptible change in the content of 

 potash in the juice while the cane is ripen- 

 ing. It thus follows that if there is any 

 relation between the proportion of potash 

 and that of glucose, it must be correlated 

 with what is termed the natural glucose 

 in the cane, namel}' that which depends- 

 on the variety and conditions of climate ; 

 but not with what is called the accidental 

 glucose, which is present through imperfect 

 maturity or over-ripeness. 



In the investigations, analyses were made 

 of juices from estates dealing with canes. 

 possessing a juice with a high purity, and 

 similarly with those grinding canes with 

 a low purity. In the same way the ex- 

 periments were extended to different va- 

 rieties of cane, choosing for comparison, 

 those giving juice of the highest purity and 

 those in which this was very low. In the 

 result, the indication was obtained that, in 

 the case of rich and pure canes, the juices 

 contained little potash ; whereas where the 

 purity of the juice was low, large quanti- 

 ties of potash were always found. The 

 same was demonstrated to be true of the 

 varieties chosen to exhibit large differences, 

 in purity. 



It therefore follows that canes possess- 

 ing the largest power to absorb potash 

 from the soil gave juice with the lowest 

 purity, and that conversely the available 

 sugar was largest in amount from canes 

 absorbing the least potash. It is, naturally,, 

 not intended that these statements should 

 discourage the employment of potash 

 manures among planters, for these are 

 necessary in order that the plant may have 

 an adequate supply of its essential food 

 bodies in the soil. 



It is pointed out that while sugar-cane 

 seedling production and selection have 

 given canes with a larger weight, there has 

 been no increase in the sugar content, but 

 rather a decrease in many instances. The 

 practical import of the investigations is 

 then expressed, namely that more attention 

 should be given in seedling cane produc- 

 tion to the sucrose sugar content, and that 

 a useful indication of this is afforded by 

 the determination of the extent to which 

 potash salts are present in the juice. — 

 Agricidtural News. 



SHREDDED CANE STORED 



At the Wisconsin Sugar Company at 

 ■Menomonee Falls nothing further has been 

 ilone with the dried shredded cane re- 

 ceived from Cuba last year. It is 'still 



stored un in the sheds of the United States 

 Sugar Company at Madison and it is said 

 it has not deteriorated in value. The man- 

 agement is planning to improve the facili- 

 ties to work up the cane as soon as this 

 year's campaign is over, and it is believed 



