NITRIFICATION AND THE FERTILIZATION OF SOILS. 71 
ART. XXIV. —RELATION BETWEEN NITRIFICATION AND 
THE FERTILIZATION OF SOILS. 
By F. Kuhlmann. 
Animal substances exert their salutary influence upon 
vegetation only when by their decomposition there is 
development of carbonate of ammonia. I have adopted 
the same view for the nitrates employed as manures ; I 
have generally regarded their influence to be effectual only 
when, by the deoxidizing action of putrid fermentation, their 
acid is converted into ammonia. To show that this con- 
version was probable, I was led to examine whether, in 
operating upon liquid products, it would be possible to ob- 
tain results analogous to those arrived at in 1838, with the 
aid of spongy platinum, in acting upon mixtures of gases or 
vapours. In the same year I showed that the production 
of ammonia, by the action of weak nitric acid upon tin, was 
not an isolated fact, but that it resulted from the action of 
this acid upon all the metals capable of decomposing water, 
and consequently the ordinary result of the contact of nas- 
cent hydrogen with nitric acid. MM. Fordos and Gelis 
have confirmed the correctness of my results, to which they 
have added several other facts, especially that of the de- 
composition of sulphurous acid by the action of nascent hy- 
drogen. 
The following are the results of some further experiments 
in support of the conversion of the nitrates into ammoniacal 
salts. When some fragments of nitre are thrown into a 
mixture of zinc or iron and sulphuric acid, or, what is pre- 
ferable, weak hydrochloric acid, the disengagement of hy- 
drogen is stopped or retarded until the whole of the nitric 
acid of the nitrate is converted into ammonia. 
Nascent sulphuretted hydrogen occasions a similar con- 
version, at the same time depositing sulphur. 
