S3 
of chlorine and carbon , &c. 
chloride had formed, but the greater part of the fluid re- 
mained unchanged. Hence, it will form even in the dark, 
by length of time. 
I tried to produce the chloride by exposure of the two gases 
in tubes over water to strong lamp light for two or three 
hours, but could not succeed. 
The perchloride of carbon, when pure, is immediately 
after fusion, or sublimation, a transparent colourless sub- 
stance. It has scarcely any taste. Its odour is aromatic, and 
approaching to that of camphor. Its specific gravity is as 
nearly as possible 2. Its refractive power is high, being 
above that of flint glass (1.5767). It is very friable, easily 
breaking down under pressure ; and when scratched, has 
much of the feel and appearance of white sugar. It does 
not conduct electricity. 
The crystals obtained by sublimation and from solutions of 
the substance in alcohol and ether, are dendritical, prismatic, 
or in plates ; the varieties of form, which are very interesting, 
are easily ascertained, and result from a primitive octoedron. 
It volatilizes slowly at common temperatures, and passes, 
in the manner of camphor, towards the light. If warmed, it 
rises more rapidly, and then forms fine crystals : when the 
temperature is farther raised, it fuses at 320° F. and boils at 
360°, under atmospheric pressure. When condensed again 
from these rapid sublimations, it concretes in the upper part 
of the tube or vessel containing it, in so transparent and 
colourless a state, that it is difficult, except from its high 
refractive power, to perceive where it is lodged. As the crust 
it forms becomes thicker, it splits, and cracks like sublimed 
camphor; and in a few minutes after it is cold, is white, and 
