SORGHUM AS A SOURCE OF SUGAR. 631 



Accordingly, in 1878, the work was commenced by Professor Peter 

 Collier, Chemist of the Agricultural Department, at Washington, and 

 his investigations were continued through the years 1879 to 1882, in- 

 clusive. 



One of the principal objects of this work was the determination of 

 the precise quality of sorghum- juices at different periods in the devel- 

 opment of the plant, in order to show at what stage the greatest 

 amount of available sugar was present in the juice. It was shown, by 

 thousands of analyses, that fully-matured plants yielded the greatest 

 amount of sugar, and that the period during which this amount was 

 maintained was full three months for some of the varieties which 

 matured most rapidly. 



It was shown that some kinds of sorghum matured quickly, and 

 were well adapted to the short, hot summer season of the Northern 

 States, while other varieties ripened more slowly, and were best adapted 

 for cultivation in the Southern States. 



It was demonstrated also that, when mature, the best of the differ- 

 ent varieties were practically identical as regards the percentage of 

 available sugar in the juice. 



The amount of crystallizable sugar in the juice of mature sorghum 

 varies between fourteen and sixteen per cent ; there are also present 

 about one to two per cent of uncrystallizable sugar ("glucose "), and 

 two to three per cent of other solids, part of which are removed from 

 the juice by the purifying processes employed in sugar-making. When 

 well purified, sorghum, cane, and beet sugar are identical in composi- 

 tion and properties. 



Among other valuable data obtained during these investigations, 

 were recorded the length of time, after seeding, before the plant reached 

 maturity ; the length of the period during which the juice contained a 

 profitable amount of available sugar (i. e., the " working period ") ; 

 the height, weight, and percentage of juice for the stalks of each 

 variety of sorghum at each stage in its development ; and numerous 

 other facts of importance to the practical sugar-maker. 



The utilization of waste, or by-products, was carefully considered. 

 It was shown that sorghum-seed is very similar in composition and 

 food-value to common Indian corn, and that the yield of twenty or 

 more bushels per acre will nearly or quite repay the farmer the cost of 

 cultivation. This seed has been successfully used for fattening cattle 

 and swine. 



It was shown that the apparently worthless skimmings obtained in 

 the clarification of the juice had a value as fertilizing material, and 

 that from the washings of the tanks and evaporators a considerable 

 amount of pure alcohol or vinegar could be produced at small cost. 



The crushed canes (" begasse "), after the removal of the juice, 

 make paper-stock of excellent quality and medium length of fiber. 

 This begasse may be preserved as food for cattle by the method known 



