928 



EXPERIMENT STATION RECORD. 



with the percentag'e di.stributioii of those constituents, arc shown in 

 the following table: 



Fcrlilizing const'dueids in c.rcriin ami milk oj.i ruics ilur'tiKj oV ilaijK. 



Suinniarizing' these results, the bulletin states: 



'"(]) The feces from milch c;ow8 contain about one-thinl of tlic nitrotrcn, three- 

 fourths of the phosplioric acid and one-sixtti of the potasli of the food. 



"(2) The urine contains one-half of the nitrogen, almost no phosjihoric acid, and 

 three-fourths of the potash of the food. 



"(;5) The milk contains less than one-sixth of tlic nitrogen, one-fourtli nf the ]>hos- 

 phoric acid, and one-tenth of the potash, or less than one-sixth of the manurial values 

 of the food. 



"(4) When the urine is allowed to run to waste, more than one half of the manurial 

 value of the food, or Go per cent of the manurial value of the solid and li(]uid manure, 

 is lost." 



Denitrification of nitrate of potash under the influence of reduc- 

 ing substances, M. Knovalov {Inr. 21<m-oir Xc/.v/-. l\hv.z. Jnst.jj {1000)^ 

 (>f. 7, 2'1'- 02-65). — This is a report of a study of the possibility of 

 denitrification occurring without the intervention of micro-organisms, 

 /. 6., under the influence of various reducing substances which occur 

 in soil. 



The first experiments were made with ferrous sulphate compounds 

 which sometimes occur in the soil. Fifteen grams of nitrate of })otash 

 and 15 gm. of crystalline ferrous sulphate were dissolved in 300 cc. of 

 water. Into this solution a current of air at 60 to 70"^ C was led 

 and afterwards passed through dilute sulphuric acid. Tests of the 

 latter by means of Nessler's reagent showed that ammotiia was slowly 

 but invariably formed at ordinary temperatures. 



All other experiments were made with humus. The hitter was pre- 

 ])ared from cane sugar l)y Herthelot's method.' The humus showed a 

 scarceh" perceptible acid reaction (to litmus) and contiiined <so to 85 

 per cent of water, but no nitrogen. 



The fii-st tests were mer(»ly (lualitative. Into each of two flasks Avere 

 introduced 300 cc. of Avater, 15 gm. of nitrate of potash, and 15 gm. of 

 humus. One flask was sterilized with water vapor at 100^ C, the 

 other by the addition of 0.4 gm. of corrosive sublimate. The stop- 



^ Ann. Chim. ct T'hys., 6. .ser., 25 (1892), p. :366. 



