672 BERZELIUS ON THE COMPOSITION OF 
as consist of carbon, hydrogen and oxygen, should properly be 
considered as carburetted hydrogen, in which the equivalents of 
hydrogen are metaleptically replaced by an equal number of 
atoms of carbonic oxide, and that such a compound can then 
combine with carbonic acid. This is evidently the doctrine of 
the union of binary compounds, corresponding to the theory of 
substitution. Thus, for instance, alcohol consists empirically 
of C* H® O?; according to Persoz, its rational formula is 
6 
=C* coe } » 2. e. in the formula C? H®, 2 equivalents of hy- 
drogen are exchanged for 2 equivalents of carbonic oxide. 
Acetic acid, on the contrary, the empirical formula of which is 
=C* H? O°, takes its origin from C? H4, in which 1 equivalent 
of hydrogen is exchanged for one of carbonic oxide, therefore 
c+ Go , and this body is then combined with 1 atom of car- 
bonic acid =cr4 do } + CO*, 
Liwig takes a view of organic composition, in which certain 
fundamental compounds of carbon or water, or both, with oxy- 
gen, can unite with carbonic oxide or with carbonic acid, or with 
both at the same time. Thus, for instance, the rational compo- 
sition of formic acid according to him is=CHO+CO%, that of 
tartrylic acid 2CHO + CO + CO, that of citric acid C? H?O 
+CO + CO?, and that of malic acid isomeric with the last 
C? H? + 2C0*. 
Graham assumes that the simple atoms of every fundamental 
principle combine with each other according to certain types 
consisting of a definite number of atoms in a fixed and un- 
changeable order. When fundamental principles unite with 
each other, then the atoms are exchanged from the types by a 
sort of double decomposition, and when organic compounds 
are produced, carbon atoms are exchanged from the carbon type 
for hydrogen, nitrogen or oxygen atoms from their types, the 
places of these latter being filled by carbon atoms. 
In this manner it is clear that anybody who undertakes to 
explain the rational composition of organic compounds and does 
not feel satisfied with what his predecessors have done, may 
fabricate or invent a new view of his own; nor is there any 
reason why this should have a limit, until some rule is sought . 
for to guide us in the mode of proceeding which ought here to 
be followed. 
