230 7.8. Hunt on the Theory of Chemical Changes. 
of carbon, as well as to the oxygen and sulphur, if we take for 
their equivalent weights, the numbers 6, 8 and 16 respectively.* 
It is to be remarked that while the co-efficients of H, Cl or N, 
in formulas where these are associated, may be odd numbers, 
those of O, S, and C are always even; this seems a conclusive 
reason for doubling the equivalents of the latter, or dividing those 
of hydrogen, chlorine, the metals, etc., according as four or two 
volumes are taken for the equivalent. yy 
I have elsewhere pointed out that carbon and oxygen sustain 
such relations, that C:H: may be compared with O2Hy» an 
with O2Mz, and by the substitution of nitrogen for hydrogen, 
with C:HN, prussic acid, and OzNz nitrous oxyd, (the so-called 
compounds of nitrous oxyd with bases are probably O2MN, cor 
responding to the cyanids, C2MN;) while the peroxyd of hy- 
drogen, OsH:2, corresponds to O.N2, nitric oxyd, and to C:Ns, 
cyanogen. This relation has important bearings on the history 
, 
of the cyanic series, and the nitric derivatives of the hydro- 
bons. 
morphous silicates, whose formulas differ by nOz Mz, as the tour . 
malines, and the silicates of alumina and magnesia, while the 
latter, with many zeolites, exhibit a similar difference of nO* 
tral 
as well as in others differing by nClz, The observations of Pas 
teur and Nicklés have greatly extended the application of thes? 
cases, which assume a new importance in connection with the 
views here brought forward, and demand further study-t 
_ But to return: we have seen that in gases and vapors, the es 
cific gravity of a Species enables us to fix its equivalent, whi 
_* See Laurent’s Récherches sur Jes combinaisons azotées, Ann. de Chimie on 
gs sig Toe 1846, and the American Journal of Science for Sept. 1848, P. ‘3 
See page 502 of my Introduction to Organic bmg ts Ra preer we 1833, 
Pit of Chemistry,” Phila.: 1852; and this Jou hoe 
ee See Laurent, Comptes Rendus de l’Acad,, t. xvi, p. 353, and p. 257 of Si 
Gahan Cpt Rendus des Travaux de Chimie for 1848 ; also Pasteur, iid, P 
dus des Travaux, for 1849, p. 347. 
