4.28 Professor Kane on the Action of Ammonia 
B. 100 grains of white precipitate, treated with iodide of potassium by the same 
method, gave sal-ammoniac 19,83, consisting of— 
Muriatic acid 13,50 
Ammonia 6,33 
F.—In all theories of the composition of white precipitate hitherto advanced, oxygen 
is enumerated as a constituent to a very considerable amount, generally so much as 
to peroxidize the whole of the quicksilver. The results hitherto obtained in my ex- 
periments would not appear to leave room for so much oxygen, and I therefore en- 
deavoured to obtain an estimate of the amount of that element by direct experiment. 
The principle of which I made use, is the following. When white precipitate is heated 
there are obtained ammonia and azote, water and calomel, but no free oxygen; there- 
fore all the oxygen of the substance has formed water at the expense of the ammonia. 
I resolved upon obtaining this water, and determining from its weight how much 
oxygen the white precipitate contained. 
A small retort was blown of strong glass, and of a capacity of from 0,2 to 0,3 of 
a cubic inch, the neck being about two inches long. ‘To this was tightly connected a 
small tube, containing sometimes dry lime, and at others fused potash, and communi- 
cating by a narrow tube with the mercurial pneumatic trough. The retort was carefully 
weighed, and the white prévipitate introduced ; the whole then weighed, and thus the 
quantity of materiel determined ; the desiccating tube was also carefully weighed ; and 
the apparatus having been connected, heat was applied to the retort until the chlorine 
and mercury had all sublimed as calomel. The water was driven completely out of 
the neck of the retort, and passed into the tube with lime or potash, where it re- 
mained. ‘The azote and ammonia were collected in a jar over the mercury. 
After the operation, the retort was weighed: the residue was calomel ; the loss, 
water, azote and ammonia: the desiccating tube was weighed ; the increase gave the 
quantity of water formed. The mixture of gases was corrected for pressure and 
temperature, and analyzed by water. 
Expt. 1st.—Retort and material 99,93 
Retort = Tae 
White precipitate 22,21 
Tube with lime before = 269,00 
Tube with lime after = 269,22 
Water condensed 0,22 
In this experiment, owing to an accident, the estimates for the calomel and gaseous 
matters were rendered unavailable. 
Expt. 2d.—Retort and material 85,25 
Retort = 64,78 
White precipitate 20,47 
