I’KESlDliXT !s AUUKESS. 
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entirely the opposite. The bodies yielding nitric acid in the soil 
arc, firstly, the various nitrogenous organic substances which arise 
from the decay of vegetable and animal matter ; and, secondly, tlnf 
ammoniacal salts produced in the course of such decay, or from 
those contained in rain, or from such salts purposely applied as 
manure ; and further, a trilling amount of nitric acid is found in 
rain water. “ The production of nitric acid both from ammonia, 
and from the organic matter of arable soil, is shown by the field 
e.\periments at liothamsted. The winter drainage water, from the 
various plots in the e.xperimental Wheat-field, is found to contain 
nitrates nearly in proportion to the (quantity of ammoniacal salts 
applied in the previous autumn ; while the drainage water, rich in 
nitrates, which is obtained from soil unman iired for eight years, clearly 
derives the greater part of its nitric acid from the organic matter of 
the soil” (Warington, “ Keport on Nitrification,” Journ. Chem. 
Soc. 1878, also Journ. Royal Agric. Soc. 187.3). 
In 1878 a report was laid before the French Academy of Sciences, 
by Schlbsing and Miintz, proving in their opinion that nitrification 
was duo to an organized ferment. This theory, they stated, was 
regarded as probable by Pasteur as early as 1862. Pasteur, in view 
of the active oxidation induced by Mycoderms in various kinds of 
organic matter, expressed the opinion that nitrification required to 
be studied over again from this point of view. It may be interest- 
ing here to note, that up to the time that I’iisteur took up the 
study of fermentation, Liebig’s theory had been in vogue; which 
was, that though ferments might be organic, nevertheless they were 
not organized, that they were nitrogenous subshinccs undergoing 
change from active oxygen. It is, perhaps, needless to say that the 
views enunciated by Pasteur, and backed up by his marvellously 
conducted experiments, practically settled the question ; and we all 
know what a wide field of evidence has since been exposed in the 
same direction. 
The experiments of Schlbsing and ^liintz werq, briefly, that of 
passing sewage which contains no nitrates, but a considerable 
amount of organic nitrogen and ammonia, through a column of 
