488 



SORGHUM. 



from the effects of a frost and subsequent warm weather — in such 

 cases the specific gravity does not necessarily give any indication as to 

 the composition of the juice. 



This is a matter of such extreme practical importance, that the fol- 

 lowing results may be considered with interest. 



In 1881, there were received at the Department of Agriculture, at 

 Washington, several lots of sorghum -cane, which had been cut several 

 days before they were delivered. The juices from these cane proved 

 to be in a very surprising and abnormal condition, and their analyses 

 are worthy of careful consideration. They were as follows : 



JUICES FROM SORGHUMS CUT SEVERAL DAYS BEFORE GRINDING. 



Dates. 



Polariza- 

 tion. 



Sucrose. 



Glucose. 



Specific 

 gravity. 



Solids. 



September '27. 



September 2S, 

 September 30 , 



Octobers 



October 4 ... 



Average 



.07 

 .00 

 00 

 1.04 

 1 05 

 70 



2 ?<0 



Iti 



2 62 



2 07 



10 85 

 U 69 

 l;? 25 

 10.78 

 10.45 



11 94 



.48 



.36 



11 49 



1.063 

 1 069 

 1 070 

 1 072 

 1 059 

 1,067 



2. SO 

 3 07 

 2 48 

 2 53 

 2.41 

 1,51 



1.067 



2.47 



We have, then, as the average of the six juices, an amount of su- 

 crose as indicated by the polariscoj^e only 14.3 per cent of the amount 

 shown to be present by analysis. AVe have also a specific gravity of 

 1.067, which indicates, as the average of a large number of analyses 

 of normal juices, a juice of the following composition, viz: 



Per cent. 



Specific gravity. 1.067 



Sucrose 11 80 



Glucose 1.99 



Solids 2.87 



It will be seen that this composition resembles the average of the 

 above six, except in this, that the sucrose and glucose appear to have 

 changed places, the sum of the two being in one case 13.79 per cent, 

 in the other 14.85 percent. 



Now, in over 4,000 separate analyses of sorghum juices from canes 

 recently cut, there has never been found even one which approximated 

 the composition of the average of these six juices above given. 



lu no case has the ^wlariscope approximately differed so widely from 

 the results of analysis as in these, for the average results of the polari- 

 scope, as compared with the results of analyses of all the juices ana- 

 lyzed, gave 96 per cent of the analytical result, while these contain 

 but 14.3 per cent. The conclusion, then, is irresistible, that these 

 juices are wholly abnormal, and are so through the inversion of the 

 sucrose which existed in the plant, since the average of all the analy- 



