Translations and abstracts from the French. 257 
Art. IX.—Translations and abstracts from the French ; by 
RoFEssor Griscom. 
Perchloride of Cyanogen and Cyanic acid. 
Specific gravity as a minerological character. 
Effects connected with Magnetism. 
Effects connected with Galvanism. 
Maximum density of water. 
A Pee ot 
. Perchloride of Cyanogen and Cyanic Acid.—A com- 
pound of chlorine and cyanogen, not before described, has 
been discovered by M. Serulas. Its formation and properties 
well corked, is exposed to the light for several days. A sol- 
id substance forms on the sides, which is to be removed, (af- 
ter blowing out with a bellows the remaining gas,) by pouring 
in a little water and a number of fragments of glass, whic. 
by agitation loosens the solid particles. These after being 
separated from the glass, are to be washed on a filter until the 
water no longer reddens litmus paper, nor forms a precipitate 
with nitrate of silver. 'The washed substance is then pressed 
and slightly warmed, between folds of blotting paper, until 
perfectly dry. It must next be distilled from a small retort, 
in the neck of which, or in the receiver, (which must be kept 
cold,) it crystallizes in needles of*a dazzling whiteness. Its 
odor is so pungent as to excite tears, especially when warm- 
ed, and has some resemblance to chlorine, but its analogy to 
the odor of mice is very striking. It is but slightly soluble 
n 
in cold water ; but much more so in hot, and is then soo 
