of Chlorine and Carbon, &c. 349 
certained by dissolving a little of the fluid in alcohol or ether, 
and testing by nitrate of silver. 
The pure protochloride of carbon is a highly limpid fluid, and 
perfectly colourless. Its specific gravity is 1-5526. It is a non- 
conductor of electricity. I am indebted to Dr. Wollaston for the 
determination of the refractive power of this chloride, and for 
the approximation to the refractive power given of the perchlo- 
ride. In the present case it is 14875, being very nearly that 
of camphor. It is not combustible except when held in a flame, 
as of a spirit lamp, and then it burns with a bright yellow light, 
much smoke, and fumes of muriatic acid. 
It does not become solid at the zero of Fahrenheit’s scale. 
When its temperature is raised under the surface of water to be- 
tween 160° and 170°, it is converted into vapour, and remains 
in that state until the temperature is lowered. When heated 
more highly, as by being passed over red-hot rock crystal in a 
_glass tube, a small portion is always decomposed ; nearly all the 
fluid may, however, be condensed again ; but it passes slightly 
coloured, and the tube and crystal are blackened on the surface 
by charcoal. 1 am uncertain whether this decomposition ought 
not to be attributed rather to the action of the glass at this high 
temperature than to the heat alone. 
It is not soluble in water, but remains at the bottom of it in 
drops, for many weeks, without any action. 
It is soluble in alcohol and ether, and the solutions burn with 
a greenish flame, evolving fumes of muriatic acid. 
It is soluble in the volatile and fixed oils. The volatile oils 
containing it burn with the emission of fumes of muriatic acid. 
When the solutions of it in the fixed oils are heated, they do not 
blacken or evolve fumes of muriatic acid. It is therefore pro- 
bable, that when this happens with the solution of the perchlo- 
ride in fixed oils, it is from its conversion by the heat into proto- 
chloride and the liberation of chlorine. 
It is not soluble in alkaline solutions, nor do they act on it in 
some days. Neither is it at all soluble in, or affected by, strong 
nitric, muriatic, or sulphuric acids. 
Solutions of silver do not act on it. 
Oxygen decomposes it at high temperatures, forming carbonic 
oxide, or.acid, and liberating chlorine. 
Chlorine dissolves in it in considerable quantity, but has no 
further action, or only a very slow one, in common day light; on 
exposure to solar light, a different result takes place. I have 
only had two days, and those in the middle of November, on 
which I could expose the protochloride of carbon in atmospheres 
of chlorine to solar light ; and hence the conversion of the whole 
of the protochloride was not perfect; but at the end of those 
two 
