of carbonic Oxide and Chlorine. 151 
were so nicely balanced, that the chlorine was nearly equally 
divided between them. And that the attraction of chlorine for 
both these gasses is nearly the same, appears to be confirmed 
by muriatic acid not being decomposed by carbonic oxide, or 
the new gas by hydrogene. 
The chlorine and carbonic oxide are, it is evident from these 
last facts, united by strong attractions ; and as the properties of 
the substance as a peculiar compound are well characterized, 
it will be necessary to designate it by some simple name. I 
venture to propose that of phosgene, or phosgene gas ; from 
(pug, light, and ytvopuzi, to produce, which signifies formed by 
light ; and as yet no other mo^e of producing it has been dis- 
covered. 
I have exposed mixtures consisting of different proportions 
of chlorine and carbonic acid to light, but have obtained no 
new compound. 
The proportions in which bodies combine appear to be de- 
termined by fixed laws, which are exemplified in a variety 
of instances, and particularly in the present compound. Oxy- 
gene combines with twice its volume of hydrogene and twice 
its volume of carbonic oxide to form water and carbonic acid, 
and with half its volume of chlorine to form euchlorine ; and 
chlorine reciprocally requires its own volume of hydrogene 
and its own volume of carbonic oxide to form muriatic acid 
and the new gas. 
This relation of proportions is one of the most beautiful 
parts of chemical philosophy, and that which promises fairest, 
when prosecuted, of raising chemistry to the state and cer- 
tainty of a mathematical science. 
