114 
as will appear presently, Dy, in others D4 and C4 were assumed 
according to VII. A. 3. For this purpose use was made of the critical 
constants of neon as published on a former occasion *) 
Ot Pee oo te Pk — 26.86 int. atm. 
The calculations were conducted in three different ways: 
a. for all temperatures only 6,4 was calculated from the obser- 
vations, the remaining coefficients being assumed, viz. C4 and Dy 
according to VII. A.3., H4 and F4 according to VII. 1 or to VII. A. 3- 
(as noticed above, this comes to the same); 
6. for the lowest 4 temperatures B4 and C4 were computed 
from the observations, further as under a; 
c. for all temperatures B4 and C4 were deduced from the obser- 
vations, for —200°.08 C., —208°.10 C. and —213°.08 C. also Dy 
and for —217°.52 C. also Zy, further as under a. 
The calculations c were made first, with a view to obtaining the 
best possible accordance with the observations, the coefficients therefore 
bearing a purely empirical character. When it appeared that the 
values of C4 could not be connected by a smooth curve, much 
less those of D4, which proved the observational material to be 
insufficient for the deduction of Cy and Dy as functions of the 
temperature, we proceeded to the methods given under a and 8, in 
which the values of D4 and partly even those of C4 were assumed. 
Naturally the accordance with the observations is very much inferior 
with the methods a and 5 than with c. 
The results of the calculations which were all conducted by the 
method of least squares are found in tables Il and lil. Table II 
gives the individual virial-coefficients, as calculated from the obser- 
vations according to a, 6, and c, table II] the coefficients borrowed 
from VII. A. 3 as well as the values of 44 computed from the equation 
A4= Aa, (1 + 0.0036618 6), *) 
where for A4, the value + 0.99986, as published on a former 
occasion *), was taken as a basis. 
1) H. KAMERLINGH ONNES, C. A. CROMMELIN and P. G. Carr, Comm. NO. 1515, 
these Proc. XIX (2) p. i058. 
2) Comm. NO. 71. 
8) Comm. NO, 147d. 
