296 



now CROPS FEED. 



iilycOCOll or CilycilIC^'= is a sweet substance that re* 

 suits from the decomposition of hippuric acid under the 

 influence of various agents. It is also a product of the 

 action of acids on gelatine and horn. 



Guanine (CJI^N^O) f occurs to the extent of about 

 ' |j per cent in Peruvian guano, and is an ingredient of 

 the liver and pancreas of animals, whence it passes into 

 the excrement in case of birds and spiders. By oxidation 

 it yields among other products urea and oxalic acid. 



kreatin (CJl^N^Oj I is an organic base existing in 

 very minute quantity in the flesh of animals, and occa- 

 sionally found in urine. 



Cameron was the first, in 1857, to investigate the assimi- 

 lability of urinary products by vegetation. His experi- 

 ments {Chejnistnj of Agriculture, pp. 139-144) were 

 made with barley, which was sown in an artificial soil, 

 destitute of nitrogen. Of four pots one remained without 

 a supply of nitrogen, another was manured with sulphate 

 of ammonia, and two received a solution of urea. The 

 pot without nitrogen gave plants 8 inches high, but thes« 

 developed no seeds. The pot with sulphate of ammonia 

 gave plants 22 inches high, and 300 seeds. Those with 

 urea gave respectively stalls s of 26 and 29 inches height, 

 and 252 and 270 seeds. The soil in neither case contained 

 ammonia, the usual decomposition-product of urea. Dr. 

 Cameron justly concluded that nrea enters plants un- 

 changed, is assimilated by them, and equals ammonia-salts 

 as a means of supplying nitrogen to vegetation. 



The next studies in this direction were made by the au- 

 thor in 1861 {Am. Jour. Science, XLI., 27). Experiments 

 were conducted with uric acid, hippuric acid, and guanine. 



'Carbon 39.73 t Carbon 32.00 J Carbon 36.64 



Hydrogen 3.31 Hydrogen 6.67 Hydrogen 6.87 



Nitrogen 46.36 Nitrogen 18.67 Nitrogen 32.06 



Oxygen 10.60 Oxygen 42.66 Oxygen 24.43 



100.00 100.00 100.00 



