352 On two new Compounds 
oxygen was made, and three volumes of it detonated with the 
vapour, as before. After cooling, the expansion was to six 
volumes, four of which were muriatic acid, and two carbonic 
oxide. There was no action on the mercury in this experiment. 
Again, five volumes of the same mixture being detonated with 
the vapour of the substance, expanded to 9°75 volumes, of which 
6:25 were absorbed by water and were muriatic acid, and 3°5 
were carbonic oxide mixed with a very smail portion of air in- 
troduced along with the fluid chloride. These experiments, I 
think, establish the composition of the protochloride of carbon, 
and prove that it contains one proportion of each of its ele- 
ments. 
From a consideration of the proportions of these two chlorides 
of carbon, it seems extremely probable that another may exist, 
‘composed of two proportions of chlorine combined with one of 
carbon. I have searched assiduously for such a compound, but 
am undecided respecting its production. When the fluid proto- 
chloride was exposed with chlorine to solar light, crystals were 
formed, as before described. The greater number of these were 
certainly the perchloride first mentioned in this paper ; but when 
the retort was examined by a microscope, some rhomboidal ery- 
stals were observed here and there among those of the usual 
dendritic and square forms. These may, perhaps, be the real 
perchloride; but I had not time, before the season of bright 
sunshine passed away, to examine minutely what happens in 
these circumstances; and must defer this, with many other points, 
till the next year brings more favourable weather. 
Compound of Iodine, Carbon, and Hijdroen 
The analogy which exists between chlorine and iodine natu- 
rally suggested the possible existence of an iodide of carbon, and 
the means which had succeeded with the one element offered 
the best promise. of success with the other. 
Iodine and olefiant gas were put in various proportions into _ 
retorts, and exposed to the sun’s rays. After a while, colourless 
crystals formed in the vessels, and a partial vacuum was pro- 
duced. The gas in the vessels being then examined, was found 
to contain no hydriodic acid, but only pure olefiant gas. Hence, 
the effect had been simply to produce a compound of the iodine 
with the olefiant gas. 
The new body formed was obtained pure by introducing a so- 
lution of potash into the retort, which dissolved all the free io- 
dine; the substance was then collected together and dried. It 
is a solid white crystalline body, having a sweet taste and aro- 
matic smell. It sinks readily in sulphuric acid of specific gra- 
vity 1°85, It is friable; is not a conductor of electricity. When 
heated, 
