297 
c. Bromine. As for want of data y cannot be directly calculated, 
we shall determine the approximated value from our formula. From 
Tr = 515,3 (Navespine, 1885) follows 2y=1,912, 7 =0,956. Hence 
we find for /,: 
re 
A oe 0,956 : 
eee ee K-02 1,912 (1—0,226) = 1,480. 
1,956 
From 7',.=— 79,3 C. = 265°,8 abs. (v. p. Praars, 1886; the latter 
found for the boiling point 63°,05 C., while Ramsay and YOUNG 
later found for it 58°,7 C.) follows namely m, = 0,462. 
As the density at 0° C. is found = 3,187 (v. D. Puaats), it will 
be at the triple point: 
D= ISR + 1,005 1,912 (0,4747 — 0,4620) = 3,213. 
In this the calculated value 1,06 has been taken for D, *). (NADEJDINE 
found 1,18). | 
As v,—111,0.10-5, we find further from f, hg 91.02 
.10-> X 1,480 = 164,3.10-5, while 165. 10 has been found from 
compounds. 
Aes 5158: 265;8 = 2,164," we get: 
fp, = 1,480 X 2,164 = 3,20. 
d. Iodine. Here too we must determine y from our approximate 
formula. With 7) — 785°.1 abs. we then find 2y = 2,065, y = 130522 
The density at 0° C. is according to Gay Lussac 4,948. But this 
value cannot possibly be correct, as Dewar found the smaller value 
4,894 at — 188°. 
If in approximation we assume continuity in the thermal expan- 
sion of the solid and liquid state — i.e. if we assume that the 
expansivity of solid iodine (about which I have not been able to 
find any values recorded) is the same as that of liquid iodine at 
low temperatures, where the vapour density can be neglected, so 
that the straight diameter can be thought prolonged unchanged as 
far as in the solid phase — then D, at the triple point 113°,7 C. = 
— 386°,8 abs. (LADENBURG, 1902; he found for the boiling point 
183°,05 ©.) can be approximately determined from 
1) This value can be calculated in two ways. First of all from vj, = 1b; = 
=b,X(y+1):y. This gives with bj, = 165. 105, y = 0,956 for vj, the value 
165 X 2,046 X 10—5 = 537,6. 10. Hence Dy, becomes = 79,92 : 337,6: 0,22412 = 
= 1,056. 
Then from the formula WoD: D= 1 + y(l—m), when the vapour density D’ 
can be neglected. With D= 3,187 at 0° GC. (m=0,475) this gives the value 
1,5935 : 1,502 = 1,061 for D,. 
