HIPPURIC ACID IN SOILS. 223 
Several bottles were examined for undecomposed hippuric 
acid, but none could be found. 
The bacterial vegetation consisted mainly of micrococci. 
Results. 
Hippuric acid and its sodium salt are not absorbed by the 
soils tested. 
Decomposition of hippurates proceeds more quickly in the 
surface soil than in the subsoil ; this decomposition is attended 
with liberation of ammonia, and is chiefly dependent upon the 
action of micrococci. 
Note to the Preceding, 
BY 
Prof. Oscar Loew. 
The fact observed by Yoshimura that nitrification does not 
take place in solutions of sodium hippurate is in accordance 
with other similar observations. The nitrifying microbes, able 
to assimilate ammonium carbonate, according to Hüppe and 
Winogradszki, cannot assimilate ammonium formate, and do 
not develope well upon ammonium oxalate, (l) as I have myself 
»ascertained. In my experiments, the sterilised solutions con¬ 
tained, (besides 0.5 per mille of one of these salts), 0.5 per 
mille each of neutral potassium phosphate, and magnesium 
sulphate, and were infected from a culture obtained from garden 
soil exhibiting a moderate nitrifying activity. The flasks, holding 
(1) The objection that the want of nitrification is not under all conditions a 
reliable sign of the absence of nitromonas, seems to me not tenable. In those cases, 
however, in which other microbes are also present, the ammonium nitrite formed can 
easily be destroyed. 
