a i 7 
F. W. Clarke on Atomic volumes of Liquids. 187 
For instance, Kopp’s earlier experiments upon a small number 
of liquids gave him the number 4°7 as the atomic volume of car- 
n (C=6), but, upon examining a larger number of com- 
pounds he obtained the number 5°5. Doubling these to agree 
with the modern atomic weight of carbon, and we have a differ- 
ence of 16. Therefore my results in the cases of the elements 
above named are useful as confirmatory of Kopp’s. My deter- 
minations for boron, bismuth, vanadium, selenium, and zine, 
Owever, are entirely new. 
The atomic volume of mercury at its boiling point I have 
calculated directly from the metal itself, by the data furnished 
by Regnault, According to this chemist, the specific gravity 
of mercury at 0° is 13°5959, its boiling point is 350°, and one 
volume of’ the metal at 0° becomes at 350°, 1:065743 volumes. 
F rom these data I find the specific gravity of mercury at its 
boiling point to be 127572, and dividing the atomic weight by 
this number I get 15°68 as the atomic volume. 
It will be seen here that I assume that mercury when free has 
the same atomic volume as when combined. This appears true 
for bromine, ammonia, cyanogen, and hyponitric acid, accord- 
ing to Kopp’s determinations, and therefore it seems allowable 
to regard mercury as following the same rule. Possibly this 
metal may have more than one atomic volume, like oxygen, 
i Having now the atomic volumes of twenty elements in their 
‘quid compounds at their boiling points, we may proceed to 
umes of compounds by Schréder and Kopp I shall have noth- 
ng to say, since more important relations between the elements 
seem to exist, 
ydrogen, having in liquids the atomic volume 5°5, is most 
readily substituted, atom for atom, by chlorine, bromine, iodine, 
Ko hyponitric acid. These have ee according to 
