162 SOEGHUM. 



The sugar-cane attains its greatest perfection within the tropics ; cold, in 

 any degree, opposes its growth and development, hence it can not be success- 

 fully cultivated in Europe, except in a very prescribed district of Spain. Even 

 in Louisiana, the frost often sets in before the planters can gather the crop, and 

 so affects the cane juice that it can no longer be induced to crystallize, unless 

 the canes can be cut and manufactured before a thaw occurs. 



This singular change in the nature of the juice is occas'oned by the fluid con- 

 tents, the saccharine and the nitrogenized principles of the various cells or or- 

 gans, bursting their bounds and becoming intermingled the one with the other. 



While the frost continues, the low temperature prevents the possibility of 

 fermentation taking place, which will altogether prevent the crystallization of 

 the juice if subsequently concentrated. 



If the thaw or period of comparatively warm weather has sufficient duration, 

 this viscous fermentation continues until all the sugar contained in the juice 

 is inverted, and the commingled fluids have resolved themselves into a 

 viscid mucilaginous matter, possessing neither sweetness nor acidity. This 

 will occur to the juice of the yet uncut cane; but it also happens to expressed 

 juice under other circumstances. Juice which has become affected in this 

 manner can not be made into crystallizable sugar, and is valuable only for dis- 

 tillation to produce rum. In the upper districts of India, also, frost frequently 

 does great harm to cane crops. 



EFFECTS OF FERTILIZERS ON SORGHUM. 



The follo^ving experiments were made with a view of determining 

 the effect of various fertilizers upon the production of sorghum, in 

 Washington, D. C. 



Tlie plat of ground, upon which were grown 37 varieties of sorghum, 

 •was 105 by 215 feet in size. The drills were lengthwise the plat, and 

 it was divided into four sections — three of 50 feet and one of 65 feet ; 

 and these plats were respectively called A, B, C, D, a corner off A re- 

 ducing its area to 6,525 feet, the others containing each 5,250 feet. A 

 sample of the soil was carefully selected from many portions of the 

 entire plat, and analyzed, Avith the following result : 



ANALYSIS OF SOIL UPON SORGHUM PLAT BEFORE APPLYING. FERTILIZERS. 



Per cent. 



Moisture 1-740 



Organic matter 4 980 



Carbonic acid -00 



Insoluble iu acids 84.2:^5 



Ferric oxide 2 864 



Alumina 4.416 



Lime • 6% 



Magnesia ^00 



Phosphoric acid ij*" 



Potash lOy 



Soda 0-^j 



Sulphuric acid "-4 



99.846 



