8. W. Johnson on Nitrification. 235 
of careful experiments, found that when alcohol, illuminating 
i i d am- 
monia are very frequently, but not always formed. When the 
combustion is so perfect that the resulting water is colorless 
and pure, only nitrous acid is formed ; when, on the other 
hand, a trace of organic matters escapes oxydation, less or no 
nitrous acid, but in its place ammonia appears in the water, 
and this under circumstances that preclude its absorption from 
the atmosphere, 
Zabelin gives no proof that the combustibles he employed 
were absolutely free from compounds o nitrogen, but other- 
wise, his experiments are not open to criticism. 
_Meissner’s observations were indeed made under somewhat 
different conditions ; but his negative results were not improb- 
ably arrived at simply because he employed a much less delicate 
test for nitrous acid than was used by Schénbein, Boettger, 
Jones and Zabelin, * 
€ must conclude then, that nitrous acid and ammonia are 
Usually formed from atmospheric nitrogen during rapid combus- 
on of hydrogen and compounds of hydrogen and carbon. 
quantity of these bodies thus generated is, however, in general 
80 extremely small as to require the most sensitive reagents for 
their detection, 
_ Formation of nitrogen compounds at low temperatures.— 
Schénbein was thefirst to observe that nitric acid may ed 
at moderately elevated or even ordinary temperatures. As is 
Well known he obtained several grams of nitrate of potas 
ympounds are formed by the simple evaporation of water. 
He heated a vessel (which was indifferently of glass, porcelain, 
silver, &ec.), so that water would evaporate rapidly from its 
e, 
dish in small quantities at a time, each portion being allowed 
.” Meissner rejected Price’s test in the belief that it cannot serve to distinguish 
mitous acid on hydric peroxyd. He therefore made the liquid to me examined 
slight exces h, concentra’ bulk 1 
dilute sulphuric acid and ferrous sulphate, (Unters. ii. d. Sauerstoff, p. 23 3). Schon- 
bein t iodid of ss is decom r a little time by con- 
Solutions of hydric peroxyd, but is unaffected by this body dilute, 
— i when dil 
Cour, fir i i with Schénbein that Price’s 
.” ‘UT prakt. Chem. Ixxxvi, p. 90.) Zabelin agrees wi n tha 
: xxx, decisive between hydric fverouya and nitrous acid. (Ann. Chem. u. Ph., 
p.58. 
. 
