402 BULLETIN OF THE BUSSEY INSTITUTION. 
The question naturally presents itself whether the occurrence of 
ammonia in anthracite may not be connected in some way with the 
pyrites that so often occur in the coal, or perhaps be due to the pres- 
ence of ferrous sulphate that has been formed through oxidation of 
the pyrites. This idea is in harmony with the action of ferrous sul- 
phate noticed above, under experiment No. V, and withthe fact that 
many lignites and alum shales contain not only very considerable quan- 
tities of sulphate of iron, but often a good deal of sulphate of ammonia 
also.* The fact noticed in this laboratory,f that commercial copperas 
often contains appreciable traces of ammonia, likewise obtrudes itself 
in this connection. It is not unlikely that one or both of these sub- 
stances may take part in the reactions by which ammonia is formed 
upon coal; but I am, nevertheless, inclined to believe that their influ- 
ence is a subordinate one in the present instance, and that the ammonia 
is really formed through the decomposition or decay of the nitrogenous 
matter of the coal, perhaps in the same way that the ammonia which 
is found in the soil may have been formed from the decay of nitrogen- 
ous organic matters. Indeed, there is little reason to doubt but that 
ammonia may be formed during the slow oxidation of organic sub- 
stances containing nitrogen that are exposed to the air. It is well 
known, for example, that ammonia is formed from such matters by the 
action of ozone,t and of other powerful oxidizing agents, such as per- 
manganate of potash, and the like. Ammonia, as well as nitric acid, 
— that is to say, nitrate of ammonia, — is often found as the result of 
the oxidation of nitrogenous matters in contact with moist earth; and 
in the familiar experiment of Stenhouse, where flesh is covered with 
bone charcoal, a faint odor of ammonia is almost always perceptible as 
a result of the process of oxidation. 
Although several of the foregoing samples of anthracite were care- 
fully tested for nitrites and nitrates, neither of these compounds were 
detected. These tests for nitrogen oxides were applied in several 
ways; namely, by adding iodo-zine starch paste to acidulated percolates 
from the coal, both before and after the liquids had been boiled for a 
short time with amalgamated zinc, or had been left standing upon 
amalgamated zine for a number of hours at the ordinary temperature ; 
* See Heiden’s ‘“ Diingerlehre,”’ 1868, 2. 356. 
t See “ American Journal of Science,” December, 1875, 10, 438. 
} Gorup-Besanez, ‘ Annalen Chemie und Pharmacie,” 125. 209. 
