WOOD SPIRIT AND ITS DETECTION. 
271 
gelatinous precipitate was formed, but slightly soluble in dilute acetic, nitric, or sulphuric 
acids, though readily dissolved by hydrochloric-, which appeared at the same time to de¬ 
compose it. The deportment of this precipitate, on the application of heat, when taken 
in connection with other considerations hereafter to be mentioned, necessarily led me to 
conclude that I had obtained a definite compound of mercury with one of the constituents 
of pyroxylic spirit. 
A considerable quantity of the naphtha was now submitted to careful distillation, and 
the portions which came over up to and at 176° F. were collected. After remaining steady 
at this temperature for some time, the boiling point rapidly rose to 182° F., and this dis¬ 
tillate was likewise collected apart from the rest. On testing the two portions with chlo¬ 
ride of mercury and potash, as before described, the first distillate gave the reaction very 
strongly, and the second not at all. The more volatile liquid was now rectified repeatedly 
from lime, and afterwards saturated with chloride of calcium. The impurities were then 
distilled off with the aid of a water-bath; and the liquid which collected in the receiver, 
when tested as before, exhibited the reaction remarkably well. The results of these ex¬ 
periments indicate, in the first instance, that pure inethylic alcohol is not connected with 
the production of the mercurial compound; and, secondly, that the body whose presence 
is essential to the resolution of the oxide of mercury has a low boiling-point. 
From this time I commenced the investigation of the mercurial compound, and have 
since succeeded in tracing it to its origin, and making out its history to some extent, as 
well as its more important chemical relations. As this is matter not essentially con¬ 
nected with the practical application of the lest, I will reserve it for the subject of a 
future communication, merely stating here, that acetone is principally concerned in the 
production of the reaction already described. 
I will now give the results of some experiments with the mercurial solution above re¬ 
ferred to, which may serve to illustrate its more distinctive characters ; I will then pass 
on to the description of a method for the detection of “ methylated spirits.” 
Experiments with Mercurial Solution. —A portion of the liquid was evaporated in 
vacuo; after a few days, it had solidified to a firm, opaque jelly; after a little time 
longer, crystals commenced to sprout out from the edges, and continued increasing daily, 
until what was formerly a jelly had become covered with beautifully formed acicular 
crystals, many of the delicate reed-like tufts reaching far above the edges of the capsule, 
and growing, as it were, out of a resinoid amorphous mass. Analysis proved that these 
crystals consisted merely of chloride of potassium, the difference iu crystalline form from 
that usually observed being due, as is well known, to the modifying influence of organic 
matter. The gummy residue remaining in the capsule after separating the crystals was 
then examined with a microscope, and found to be totally destitute of crystalline struc¬ 
ture, the detached pieces being smooth and rounded, very brittle, and semi-transparent. 
When heated to a temperature of about 450° F., it swelled up considerably, at the same 
time evolving a quantity of mercurial and empyreumatic vapour, and leaving a volu¬ 
minous residue of carbon. When the original solution was boiled violently, a white 
gelatinous precipitate was formed, readily soluble in dilute hydrochloric acid, though ap¬ 
parently but slightly acted on by dilute acetic, nitric, or sulphuric acids. 
Excess of acetic acid was now added to another portion of the alkaline solution, and 
the resulting precipitate thoroughly washed, and then transferred to a retort; some 
hydrochloric acid was now added, and the mixture distilled. The distillate, when tested 
with chloride of mercury and potash in the usual manner, gave the reaction very strongly. 
Some solution of chloride of mercury and a few drops of the naphtha were mixed, and 
then excess of potash added, which caused the resolution of the oxide of mercury with¬ 
out the aid of heat. A portion of this solution, on the cautious addition of an acid, did 
not give any precipitate. The mixture was now gently warmed, and afterwards acetic 
acid added, upon which a precipitate was immediately formed. 
From the results of these experiments, the following information may be gleaned :— 
1st. That the compound in question is somewhat resinoid in character, and destitute of 
crystalline structure; 2ndly. It is precipitated by boiling, or on the addition of an acid ; 
3rdly. It is easily decomposed by hydrochloric acid, the organic body passing off apparently 
unchanged; and 4thly. It is always necessary to employ heat previous to the addition of 
an acid, otherwise no precipitate will be produced immediately. A consideration of the 
first of these points, viz. the want of crystalline structure, the gelatinous appearance, and, 
in fact, tli« colloidal nature of the compound in question, led me to resort to the beau- 
u 2 
