160 



SORGHUM. 



The average results obtained by the polariscope before the frosts was 

 97.35 ]oer ceut of those obtained by analysis, while the results after the 

 frosts were only 90.84 per cent. This result is, in all probability, due 

 to the presence of inverted sugar in the juice, as is indicated by the 

 increase of glucose, which increase amounts, upon an average, to 1.62 

 per cent of the juice. 



The increased percentage of sugar in these juices, obtained after the 

 frosts, must not be regarded as an actual increase of sugar in the plant; 

 for, on the other hand, there has been a very considerable loss of sugar, 

 as is indicated, not only by the increase in the glucose, which now con- 

 sists largely of inverted sugar, as the polariscope determinations show, 

 but there has been a very large loss of juice, showing a loss of water. 

 Indeed, there seems in this case to have been a gradual drying vip of 

 the water of the plant ; and the increased per cent of sugar shows 

 only that the inversion of the sugar and the fermentation and disap- 

 pearance of the glucose did not proceed quite as rapidly in proportion. 



Tlie following table will show the relative composition of the juices 

 before and after these frosts, and the results calculated to the stripped 

 cane: 



Juice froin stalks. .i 



Sucrose in juice 



Glucose in juice 



Solids in juice 



Total solids in juice 



Available sugar in juice 



Water in juice 



Snnrose expressed from stalks 



Glucose expressed from stalks 



Solids expressed from stalks 



Total solids expressed from stalks ... . 

 Available sugar expressed from stalks: 

 Water expressed from stalks 



From the above it will be seen that the effects of these frosts upon 

 the several constituents of the juices, calculated to the stripped stalks, 

 showed 



Loss of sucrose 22.38 per cent, or 1.62 per cent of stalks. 



Gain of glucose 56.34 per cent, or .40 per cent of stalks. 



Loss of solids ... 25.00 per cent, or .39 per cent of stalks. 



Loss of total solids 16.93 per cent, or 1.61 j.er cent of stalks. 



Loss of available sugar 32.80 per cent, or 1.63 per cent of stalks. 



Loss of water 35.77 per ceut, or 17.41 per cent of stalks. 



These results above detailed must not be regarded as in conflict with 

 the conclusions published in the annual report 1881-82, p. 502, where 

 the increase in sugar during the later stages in the development of the 

 sorghum was shown not to be due to a loss of water by drying up of 



