312 
T,. == 1320 abs. with our approximate formula, /, would be 
— 9,52, only slightly divergent, therefore, from the value 9,93 found 
just now for the equilibrium solid-vapour, calculated at 830° a 
870° abs. 
With y—=1,19 we can now aiso calculate the factor f,. We 
find: (m, = 1090 : 1320 — 0,826): 
1,19 : . | 
== 2,38 |: lees ee 04826 | = — 2,38 (1 — 0,449) — 1,312. 
Now we ought to know the density at the triple point. But the 
calculation of this from the given density at 14° C. is rather un- 
reliable, as 817° is too far from J4° C., and also the application of 
the coefficient of expansion determined at 50° C. is certainly not 
valid. In order to be able to determine the value of bj. notwith- 
standing with some approximation from the density at 14° C., we 
shall calculate f for this témperature (Z7’= 287, m= 0,217). We 
find then: | 
| 1,19 
f = 2,38 |" ees ou |=: 2,38 (1—0,118) = 2,099. 
As v=71,2.10~ corresponds to D—4,7 (amorphous), 5, would 
become — 150.10 ” instead of 195.10 5. Prodably, therefore, the 
assumed value of D is too high. Only with D— 3,62 we should 
have found the expected value of hj. In this connection we remark 
that D—3,70 has been found for the amorphous brown-black 
Arsenicum (GeEurnen, 1887). Then A: D would become == 20,26, 
v = 90,40. 10-2, hence 56; = 190.10 °, which comes nearer to the 
theoretical value 195.10). 
We arrive, therefore, at the right result, if only the density of 
the “brown-black” modification, which is much slighter than that 
of the amorphous Arsenicum, is taken as the foundation of the 
calculation. 
We find for the product fu, 
1) If ‘for this modification we apply the formula of the straight diameter as 
first approximation, then 
D, + D, =3,1 — 0,932 Xx 2,38 (0,826 — 0.217) = 2,35 
would follow from DH Di = (D-+ D’) — Dg X 2y (m—™m), when D' is neglected 
at 14° C., and the value 0,932 is taken for the calculated value D, . 
And as generally be =[A: (D, + D,'): 22412] X fi, be becomes = 142,3. 10-5 & 
X 1,312 = 187.10—5 for 1 Gr. atom, also in the neighbourhood of 195. 10-5, 
The value assumed just now for Dx follows from the relation (These Proe. loc. — 
: 4 2,19 
cit;) up = 7b, = dek be me 195. 10-3=358,8. 10-5. Expressed in ordinary 
Y ‚Le 
units this is 358,8. 10-5 X 22412 = 80,41; for 1 Gr. therefore 80,41 : 74,96 = 1,073. 
Hence Dx = 0,9322. 
