CIRCULAR NO. Ill, BUREAU OF PLANT INDUSTRY. 



CLARIFICATION AND EVAPORATION. 



To the mixed juice, milk of lime was added to a slight alkalinity, as shown by litmus 

 paper. The lime used contained about 40 per cent magnesium. The whole was 

 then heated nearly to boiling or to a point where the scum easily separated from the 

 clear juice. The heat was then turned off and the juice allowed to settle. The clear 

 juice was then filtered off, brought to a boil, and skimmed. 



In order to test the effect of concentration in acid solution, water saturated with 

 sulphur dioxid was then added to the boiling juice until it was decidedly acid to 

 litmus paper. The whole was then evaporated to a sirupy consistency. The analy- 

 sis of the juice after sulphuring but before evaporation showed the following com- 

 position: 



Table IV. — Analysis of juice after sulphuring. 



By the use of lime and sulphur dioxid it is seen that there had been a rise in purity, 

 which indicates a clarification by removal of some of the organic material. When this 

 concentrated material had reached a proper density, as told by appearances, it was 

 allowed to cool slowly. Crystals of sucrose did not appear immediately, but after a 

 week well-defined crystals of sucrose were noted. These continued to grow. 



COMPARISON OF CORN WITH SORGHUM AND SUGAR CANE. 



In order to show the relative value of corn as a source of sugar in 

 comparison with other sugar-producing plants belonging to the grass 

 family, Table V has been prepared. 



Table V. — Comparison of corn with sorghum and sugar cane as a source of sugar. 



i Average of analyses of 20-stalk samples of four varieties (Early Amber, Coleman, Orange, and McLean) 

 grown at Garden City, Kans., in 1912 in the same field as the corn. 



2 Average of analyses of D. 74, D. 95 and home canes for nine years, 1895 to 1903. See Stubbs, W. C, 

 and Blouin, R. E., Comparative results of seedling sugar canes, D. 74 and D. 95, with our home sugar 

 canes (Louisiana Striped and Louisiana Purple), Louisiana Agricultural Experiment Station Bulletin, 

 s. 2, no. 78, p. 7-11, [1904]. 



3 Average of analyses of 17 varieties of plant cane harvested in 1904 and ratoon crop from the same plant- 

 ing harvested in 1906. See Eckart, C. F., Comparative tests with varieties of sugar cane, Hawaiian Sugar 

 Planters' Association, Division of Agriculture and Chemistry, Bulletin 17, p. 6. 



The corn grown at Garden City from which the ears had been 

 removed was higher in solids than either sorghum or Louisiana 

 [Cir. in j 



