July 9,1870.] 
THE PHARMACEUTICAL JOURNAL. 
23 
the gas will pass up the chimney in the state in which 
it left the fire, that is, imperfectly burned ; and thus 
we have hydrocarbons in the gaseous products of the 
combustion of coal. This is the first hypothesis I 
have to present. 
The second hypothesis rests on the observation of 
M. H. Sainte-Claire Deville. At the moment when the 
hydrocarbons are disengaged, being brought to a 
very high temperature, they behave like a mixture 
of carbon vapour and hydrogen. If a sufficient 
quantity of air were supplied to this gas, its combus¬ 
tion would be complete ; otherwise it would be im¬ 
perfect, and we should have the result of a cooling 
more or less rapid. If the cooling should take place 
quickly, as would happen when it comes in contact 
with surrounding cold objects or cold air, a separa¬ 
tion of carbon in the form of soot would occur, and 
free hydrogen would be left, which thus accounts for 
the presence of this element, as well as hydrocarbons, 
in the gaseous products of combustion, some of the 
hydrocarbons resulting from recombination of the ele¬ 
ments, as explained by Deville. 
Again, the third hypothesis rests on the observa¬ 
tion of M. Berthelot. The hydrocarbons distilled 
from the coals are submitted to the heat of the fire, 
and decomposed. They form new compounds with 
deposition of charcoal, or, in other words, with the 
production of smoke. If there should arrive a suffi¬ 
cient quantity of air, the combustion of the whole 
will take place, but if there is a deficiency of air, the 
smoke will remain, together with the new hydrocarbon. 
It is thus that smoke is produced. We have seen 
that there is always a deficiency of air as a neces¬ 
sary cause. This statement may appear extraordi¬ 
nary, as it has been found that the gaseous products 
of the combustion of coal always contain an excess 
of air. This, however, is not inconsistent with the 
previous statement, for in saying that there is a de¬ 
ficiency of air, what is meant is that this is the case 
in each volume or stratum of air in which combus¬ 
tion has taken place, but the gases which pass into 
the chimney may be regarded as a collection of such 
volumes mixed with others rich in oxygen, and these 
would be too much cooled to admit of their entering 
into combination. 
It results from these theoretical considerations, 
that for the purpose of avoiding or diminishing 
smoke, it suffices to cause the intimate admixture of 
the gases the moment they quit the fire. In fact, 
this method lias been practically applied with suc¬ 
cess. The first application of these principles was 
made by M. Harteg.* 
The furnace of M. Harteg consists of two fire¬ 
places, side by side, running parallel, and separated 
by a wall. The fires in these two fireplaces are fed 
alternately, and the currents of gas being directed 
one against the other at the back of the furnace, the 
strata are thus broken up and mixed so as greatly to 
diminish the amount of smoke. 
M. Brixf diminishes greatly the amount of smoke 
or prevents it altogether, by introducing a little air 
in a minutely divided state behind the bridge of the 
furnace. This air supplies the required oxygen at 
the moment when the combustible gases are still 
sufficiently heated for them to become ignited, and 
the admixture is readily effected, but with some loss 
<of combustible matter. 
'* Harteg, ‘ Sur la Combustion des Houilles de Saxe.’ 
•f Brix, ‘ Sur la Combustion de la Houille de Prusse. 
Lastly, M. Thierry’s process consists in introdu¬ 
cing a jet of steam over the surface of the fire. The 
steam does not exert any chemical action, but ope¬ 
rates mechanically by mixing the gases, and thus 
diminishes the amount of smoke. 
The following experiment I have repeated fre¬ 
quently, and always with the same results:—If a 
metallic tube be introduced into the current of gases 
in the furnace by passing it through a hole in the 
brickwork, the following observations may be made, 
—when the tube is kept cold by an external current 
of cold water, a large quantity of soot will be depo¬ 
sited upon it, which will increase until the action of 
the cold water ceases. If the current of water be 
stopped, and the tube allowed to become hot, the soot 
will gradually disappear, and will not be again de¬ 
posited under these circumstances but its formation 
may be at once determined by renewing the cooling 
process. After the explanation I have given of the 
production of smoke, the foregoing result is easily 
explained. The dissociated gases coming into con¬ 
tact with a cold surface, deposit the carbon, but at a 
sufficiently elevated temperature this combines with 
oxygen and passes off as carbonic acid.— Reper¬ 
toire cle Pliarmcicie. 
ON DE LOSSEN’S OXY-AMMONIA. 
BY M. E. FB.EMY. 
In a previous communication on nitrous acid I an¬ 
nounced the production of a body possessing reducing 
power in a high degree, and which is formed when 
nitrous acid or nitrites are submitted to the action of 
hydrogen, sulphuretted hydrogen, sulphurous acid, the 
alkali metals, zinc, tin, etc. 
I was unable immediately to determine the nature of 
this body, and ascertain whether its composition was 
NH 3 0* as thought to be the case by Maumene, whose 
publication on the subject has been of great use to me, 
because by the method I then adopted I obtained it in 
quantities insufficient for the purpose. 
I have recently discovered a method of easily pro¬ 
ducing this derivative of nitrous acid, and have accu¬ 
rately determined its characters and nature. I have 
found that it possesses very marked basic properties. 
I prepare it in the following manner:—1 treat tin 
with concentrated hydrochloric acid, inducing chemical 
action by a slight elevation of temperature; when hy¬ 
drogen is abundantly produced, I add to the liquor either 
nitrous acid or a nitrite, or, more simply, nitric acid; I 
precipitate the protoxide of tin with ammonia; evapo¬ 
rate the liquor to dryness by means of a water-bath, or 
in vacuo ; and lastly, treat the dry residue several times 
with absolute alcohol, which dissolves the hydrochlorate 
of the base. 
The circumstances under which this basic substance 
has been produced, and the way in which it is prepared 
led me to think that it is nothing else than oxy-ammonia, 
the important discovery of which is due to M. Lossen. 
The formula for oxy-ammonia, NH 3 0, which might 
otherwise be written, N 2 H 4 0.H 2 0, shows, among other 
things, that oxy-ammonia might be considered to be a 
hydrate of nitrous acid (nitrous anhydride) in which two 
atoms of oxygen are replaced by an equivalent quantity 
of hydrogen. Its production by the reducing action of 
hydrogen on nitrous acid or a nitrite, is thus perfectly 
intelligible. 
But for the further elucidation of the subject, thus 
assuming so simple an aspect, two points remained to bo 
determined. 
* The notation in this paper has been changed from that 
used by the author to the new notation now used in this 
country. 
