176 EF. W. Clarke on the Atomic Volume of Compounds. 
simply concerns the distribution of the changes of volume un- 
dergone by the various elements in uniting to form compounds. 
Second. It has been shown, most definitely by Schroder and 
Kopp, that, in many cases, when from the atomic volumes of 
certain series of salts, oxyds, &c., we subtract the atomic volumes 
of the respective metals contained in them, we obtain constant 
remainders which may be regarded as representing the values of. 
the various radicals and of oxygen. Thus, if from the atomic 
volumes of one class of oxyds we remove the values of the metals, 
we obtain the remainder 2°6. With other oxyds we get 52, and 
with still others, 10-4. ese are provisionally regarded as the 
atomic volumes of oxygen in its solid compounds. These dif- 
ferent values for a single element are of course natural conse- 
again. 
Third, wecome to some results which I myself published 
rather more than a year ago.* In my last paper upon this sub- 
ject I pointed out some curious multiple relations connecting 
the atomic volumes of similar solid elements. For the proofs 
of these relations I must refer to the above mentioned paper, 
but the values for the elements themselves I am obliged to cite 
here for further reference. I give the values for solids only. 
Li 11-4, Na 22°8, K 45‘6, Rb 57-0. These stand to each other 
as 1:2:4:5. I 25-6, T1172, Ag and Au 102. 
Here arises an interesting question. The atomic volumes of 
Ag and Li are quite near together. But the specific gravity of 
lithium was determined comparatively near the melting point of 
that metal, while that of silver was taken at a temperature 
greatly removed from the degree at which it fuses. Now melted 
silver, according to Playfair and Joule, has the specific gravity 
‘206; and consequently an atomic volume of 11°7, nearly that 
of solid lithium. May not these two metals then, under simi- 
ar circumstances, and at strictly comparable temperatures, be 
supposed to have equal atomic volumes? 
O 2°6, 52,104 S104, 156. Se 104, 15°6(?7) Te 20%. 
This value for S is that of the octahedral variety, prismatic 
a * This Journal for March and May, 1869. 
