$72 On definite Proportions. 
than those which have hitherto been considered as com= 
binations with oxygen at a minimum; sulphur, for in= 
stance, and iron. With respect to the latter, in particular, 
I have conjectured that iron may exist in organic bodies in 
such a lower degree of oxidation. The products of organic 
nature will not, at first sight, agree with the Jaws to which 
T have been led for the composition of unorganized bodies: 
‘it was therefore my intention to undertake, in a future 
essay, the examination of organic bodies, and to begin with 
the simplest, the oils and the vegetable acids. But the 
more I have employed myself in these experiments, the 
more I have been convinced, that the chemical data re- 
Jating to organie bodies are not yet numerous enough, and, 
with very few exceptions, not sufficiently accurate. I shal] 
therefore content myself with showing in what manner, by 
investigations of inorganic nature, we may gradually arrive 
at resulis which are to be expected in organized bodies. 
We will begin with the lower degree of oxidation of 
sulphur, which has been mentioned as a conjecture, and 
endeavour to determine it, by calculation, from the analysis 
of sulphureted hydrogen, according to the analogy of the 
combinations of carbon with oxygen and with hydrogen, 
which we must therefore examine more particularly in the 
first place. 
1.) Carbon and Oxygen. 
According to Allen and Pepys, 100 cubic inches of car- 
bonic acid gas weigh 47:26 grains, and 100 cubic inches 
of oxygen gas 33°82 grains; the carbonic acid gas contain- 
ing also an equal bulk, that is, 33°82 grains of oxygen, 
‘and consequently 13°44 of carbon: according to their di- 
rect experiments, 100 parts of carbonic acid consist of 
28:48 parts of carbon (from graphite or plumbago); and 
according to the statical experiment, of 
Carbon........ 28°437 300-000 
Oxyhens S24 Tes 79 S6S 251°636 
According to Gay-Lussac’s experiments, 100 cubic inches 
of gaseous carbonic oxide condense 50 cubic inches of 
oxygen, giving 100 of carbonic acid. If we substitute 
weight for measures, we find in the gaseous oxide a com- 
bination of carbon with half as much oxygen asin carbonic 
acid gas, and it consists of 
Carbon ., .... 44°283 100-000 
AVPCU ge wegss Ql] ty 125°818 
2.) Carlon and Hydrogen. 
Thomson asserts, in his analysis of the combustible gas 
; which 
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