Translations and abstracts from the French. 'ibl 



Art. IX. — Translations and abstracts from the French j by 



Professor Griscom. 



1. Perchloride of Cyanogen and Cyanic acid. 



2. Specific gravity as a minerological character. 



3. Effects connected with Magnetism. 



4. Effects connected with Galvanism. 



5. Maximum density of water. 



1 . 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 

 are stated in an interesting memoir read before the French 

 Academy, on the 28th of July and 1st of Sept. 1828. 



The new substance is obtained by pouring into a quart 

 flask, full of dry chlorine, fifteen grains of pure hydro-cyanic 

 acid, prepared by Gay Lussac's method. The flask being 

 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 httle water and a number of fragments of glass, which, 

 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 

 in cold water ; but much more so in hot, and is then soon 

 decomposed. Alcohol and ether dissolve it easily, and from 

 these solutions it is separated by water. Its aqueous solution 

 at common temperature, is slowly decomposed, and the li- 

 quid becomes acidified more and more. By ebullition, 

 somewhat prolonged, all the perchloride disappears ; there 

 is no disengagement of gas, but a production of hydro-chloric 

 acid, and cyanic acid., which in this case, must be formed of 

 one atom of cyanogen and two atoms of oxygen. 



Vol. XVI.— No. 2. G 



