M. Serullas on Hydriodide of Carbon. 301 



the carbon disappeared, which he knew positively to exist in 

 the hydriodide. 



He had occasion to observe, in these experiments, that the 

 sub-chloride of iodine, treated by ammonia, threw down, at the 

 moment, the iodine, in the state of a very fulminating iodide of 

 azote ; and that there was formed scarcely any hydriodate of 

 ammonia. We can understand this, since the chlorine, which in 

 this case decomposes the ammonia, ought exclusively to seize 

 the hydrogen, leaving the azote to the iodine. By the common 

 process of putting iodine into water of ammonia, only one- 

 fourth of the iodine is converted into the fulminating compound. 



The facility offered by chlorine, of converting the hydriodide 

 of carbon into chloride of iodine, and consequently into iodate 

 and hydrochlorate, by its solution in water, and saturation with 

 potash, appeared to M. Serullas, after other trials, to be the 

 most exact means of ascertaining the quantity of iodine which 

 enters into the composition of the hydriodide of carbon. He 

 treated a number of times with chlorine, given quantities of 

 hydriodide of carbon ; the resulting chloride of iodine, being 

 dissolved in water, and saturated with potash, constantly pro- 

 duced the same quantities of iodate, at least with so slight 

 diflferences, that we may indicate, without fear of deviating from 

 the truth, 1.5 gramme as the mean product, for each gramme 

 of hydriodide. The iodate of potash being formed of 77.54 acid 

 and 22.246 potash ; the iodic acid of 100 iodine and 31.927 

 oxygen; every gramme of hydriodide of carbon will then contain 

 0.8992 of iodine. 



M. Serullas analyzed the compound also, by ignition with 

 oxide of copper ; from which he infers it to consist of, 

 Iodine . 0.8992 1 atom 

 Carbon . 0.0864 2 atoms 

 Hydrogen 0.0144 2 atoms. 



1.0000 

 Ann. de Ch. et de Phy. xxii. 172. 



Supplementary to the above information, M. Serallas has in- 

 serted in the same Journal a letter to M. Gay-Lussac, on the 

 subject, in which he says, that he finds hydriodide of carbon may 

 be very abundantly obtained, by simply treating an alcoholic 

 solution of iodine with an alcoholic solution of caustic potash, 

 or soda. The formation of hydriodide of carbon, in this case, 

 proves very manifestly the decomposition of the water ; just as 

 the formation of an iodate with excess of acid, from the first 

 instants of the saturation of a solution of chloride of iodine, 

 seems to prove the pre-existence of iodic acid in the solution ; 

 and consequently to confirm its being a mixture of iodic acid 

 and muriatic acid, as M. Gay-Lussac has said. 



