366 Luboratory Occurrences, 
cipitated, but was less abundant in quantity than usual. Re- 
peating the experiment, in the same manner, the gases had 
remained in contact a few minutes, apparently without ming- 
ling much except at their surfaces—the chlorine preserving 
its peculiar colour and the other gas its colourless transpa- 
rency, when, suddenly, a bright flash pervaded the bell glass, 
which was of the capacity of five or six quarts; it was raised 
out of the water with a slight report—a dense deposit of char- 
coal lined the glass and floated on the water of the cistern, 
and the chlorine disappeared. The appearances were much 
like those which are exhibited when a rag dipped in oil of 
turpentine is placed in a jar of chlorine gas. 
Reflecting on the circumstances, I was led to believe that 
the peculiar effect, in this case, arose from the fact, that, 
owing to the great difference in the specific gravity of the two 
gases, the action took place principally at the two surfaces 
of contact and thus the chlorine acting upon a comparatively 
thin stratum of inflammable gas, the two became so heated, 
as to pass into vivid combustion. Hvery new occurrence in 
practical chemistry, which may involve danger, ought to be 
exactly stated, that we may be aware of contingencies not 
otherwise anticipated. 
2. Explosion of Pyrophorus. 
A preparation of this substance, having been made, was 
ieft eight or ten days well corked, in iron tubes, (the same in 
which it was prepared,) and being opened, for transferring 
to another vessel, a common ramrod was introduced, to 
loosen the pyrophorus, the motion of which, produced 
considerable friction ; when an explosion took place, loud as 
acommon musket, by which the contents of the tube were 
blown out in a jet of fire, two or three feet long, scorching 
the hair and eye-brows of the person conducting the opera- 
tion, and a violent jerk was given to the hand that held the 
ramrod. he glove, with which his hand was fortunately 
covered, was burnt in several places to a crisp. His eyes 
and whole face were affected in the same manner as if gun 
powder had been discharged against them ; and this sensa- 
tion continued several days, passing off, however, without 
serious inconvenience. On putting the ramrod into a second 
tube, containing pyrophorus, and very cautiously and gently 
touching the substance with the end of the rod, another ex- 
plosion took place. equally violent as the first, Tt was not 
