47G SORGHUM. 



The results of thirty determinations may be stated as follows : 



Per cent. 



Sugar solution containing 9 67 



No. 1. Four determinations, by titration (average) 9 57 



No. 2. Nine determinations, by titration (average) 9 74 



No. 3. Fifteen determinntions, by titration (average) 9.77 



No. 1. One polarization 9 63 



No. 2. One detenninaiion of total solids 9.70 



The lowest result was ■ 9 50 



The highest result was 9 98 



It may be assumed, therefore, that the greatest error is not more than 

 minus one-tenth or 2}li(s three-tenths of one per cent, which, in the work 

 under hand, can not be considered excessive. 



In order to have a check on the process, when apphed to juices as 

 well as pure sugar solutions, polarizations were made in a large num- 

 ber of cases. The following table gives a series of average results for 

 several years. 



COMPARISON OF ANALYSIS WITH POLARIZATION OF SORGHUM JUICES. 



In the examination of sorghum juices in 1882, there was taken, 

 for the purpo.se of controlling analytical results, the polarization of the 

 juices. In all, 855 juices from the several varieties of sorghum under 

 cultivation, and in every condition of development, were thus exam- 

 ined, and the average results are as follow : 



Per cent. 



Sucrose by analysis 10 938 



Sucrose liv polarization 10.969 



Or as 100 : 100,265. 



The first 548 analyses made gave even closer results, viz.: 



Per cent. 



Sucrose by analysis 10..5H,> 



Sucrose bv polarization. 10.577 



Or as 100.074 : 100. 



The above results prove that the analytical method employed in 

 these investigations is as accurate as could be desired, and that the re- 

 sults secured by this method are entitled to entire confidence in their 

 substantial accuracy. 



In 1881, the average results of 697 analyses of sorghum and 103 

 of maize j uices gave : 



Per cent. 



Sucrose by analysis 10. .598 



Sucrose bv polarization 10.161 



Or as 100 : 95.9. 



The following table shows the results of analyses and polarizations 

 of the juice, arranged according to the per cent of sucrose in the 

 juices, from 1 to 19 per cent in the sorghums, and from 1 to 14 per 

 cent in the maize juices. It will be seen that the agreement is as 

 close between analysis of juices poor in sugar and comparatively rich- 

 est in glucose, as between the best juices. This is very important, as 



