316 F. W. Clarke on the Atomic Volumes of the Elements. 
and Jobin), that of barium is 40 (Clarke), that of strontium 
2-5418 (Matthiessen), and that of lead is 11°37 (Reich.) Hence 
the atomic volumes are respectively 25°8, 342, 34°3, and 182. 
These numbers approximate very closely to multiples of the 
lowest value for oxygen, 2°6. The number for lead requires 
no change whatever, that for calcium but 0-2, and those of 
barium and strontium but from 0°4-0°5, to produce the exact 
multiples. Whether this relation is accidental or not, it 18 
impossible for me to say, but the coincidence is certainly te 
markable. 
Another similar relation we find between the atomic volume 
of the diamond, and those of certain metals which are often 
classed as tetratomic. The sp. gr. of glucinum is 2°1 (Debray), 
that of aluminum 2:56-2°65 (as given in the ‘ Handworter- 
buch), and that of thorium 7-657-7°795, (Chydenius). Hence 
their atomic volumes are respectively 6°7, 10-1-10°6, and “4 
309. The atomic volume of the diamond is 3°4, that of glu- 
cinum wants but 0°1 of twice that, three times 3°4 is within 
the limits between which aluminum varies, and nine times 34, 
The remaining metals, as far as we have data, seem t0 find 
places in none of the previous series. Thallium, according ug 
Crookes, has a sp. gr. of 11-81-11:91. Its atomic volume, 
then, is 17-2. Winkler gives the sp. gr. of indium as 7421, 
which corresponds to an atomic volume of 102. For niobium, 
tantalum, lanthanum, didymium, yttrium, and erbium, ¥° 
have no data whatever. gies 
e sp. gr. of iodine is 4947 (Handworterbuch). This giv 
as its atomic volume the number 25°6, almost exactly 
thirds of its value in its liquid compounds. The atomi¢ YO" 
umes of bromine and fluorine in their solid compounds I ee 
not been able to calculate in any satisfactory manner from * 
ata at my command, since the values obtained did not agree 
with each other. The atomic volume of chlorine in solids, ai 
been calculated by Kopp, who obtained two values; bi 
between these and its value in the liquid state I have found 20 
relations, 
_ For hydrogen, the data at hand are quite complicated, 
being in any connected series of compounds, and as far 38 
have been able to decide, it appears to have several values: 
However, in some of its solid compounds, hydrogen seems = | 
