THE XITUOr.ENOUS nUNt'irM.EH OF URINE. 297 



Washed and ignited flower-pots were employed, to con- 

 tain, for eacli trki!, a soil consisting of 700 grms. of 

 ignited and -washed granitic sand, mixed with 0.25 grni. 

 sulphate of lime, 2 grms. ashes of hay, prepared in a muffle, 

 and 2.75 grms. bone-ashes. This soil was placed upon 

 100 grms. of clean gravel to serve as drainage. 



In each of four pots containing the above soil was de- 

 posited, July 6th, a weighed kernel of maize. The pots 

 were watered with equal quantities of distilled water con- 

 taining a scarcely appreciable trace of ammonia. The 

 seeds germinated in a healthy manner, the plants devel- 

 oped slowly an<l alike until July 28th, M'hen the addition 

 of nitrogenous matters was begun. 



To No. 1, no solid addition was made. 



To No. 2 was added, July 28th, 0.420 grm. uric acid. 



To No. 3 was added 1.790 grm. hipjjuric acid, at four 

 different times, viz: July 28,0.358 g!5m.,Aug. 26th, 0.358 

 grm., Sept. 16th, 0.716 grm., Oct. 3d, 0.358 grm. 



To No. 4 was added 0.4110 gim. hydrochlorate of gua- 

 nine, viz: July 28th, 0.0822^ grm., Aug. 26th, 0.0822 

 grm., Sept. 16th, 0.1644 grm., Oct. 3d, 0.0822 grm. 



The nitrogenous additions contained in each case, 0.140 

 grm. of nitrogen, and were strewn, as fine powder, over 

 the surface of the soil 



The ^ilants continued to grow or to remain healthy (the 

 lower leaves withering more or less) until they were re- 

 moved from the soil, Nov. 8th. 



The plants exhibited striking diffei'ences in their devel- 

 opment. No. 1 (no added nitrogen) produced in all seven 

 slender leaves, and attained a height of 7 inches. At the 

 close of the experiment, only the two newest leaves were 

 perfectly fresh ; the next was withered and dead through- 

 out one-third of its length. The newer portions of this 

 plant grew chiefly at the expense of the older parts. No 

 sign of floral organs appeared. 

 13* 



