5 Ko. Tr, $ Pk, bas Tr, Pk, 
while : ei | View ho . 
Ky, Tx, Pk; by) Tk, Pha 
In this way I find for methyl chloride with carbon dioxide as 
admixture:: 
a — — 0.236, @—0.113, 
and for carbon dioxide with methyl chloride as admixture: 
a = 0.426, B= — 0.108, 
which values, if we take into consideration that @ has by far the 
greater influence, agree sufficiently with the values derived directly 
from the observations in § 3, to enable us to apply these formulae 
also to ethane and butane. For butane no critical data are known 
to me. From the regular succession of the critical constants determined 
by Youne for the members of the paraffin-series following butane: viz. 
| t, | Direc Py Difference. 
Normal pentane 197.2 25100 m.m. 
31.6 2590 
» hexane 934.8 99510 
32.4 2095 
» heptane 266.9 20415 
29.3 1685 
» octane 296 2 18730 
we are justified in concluding that we may assume for butane : 
tr = 152, pp = 28300 m.m. = 37.2 atm. 
With the values for ethane: 
G =s20, pe = 48.84), 
this yields : 
a=0.47, 6= — 0.36. 
k dn 
The values of zr, DER wy and @, were borrowed from YouNne@’s 
T 
observations on pentane ; 
{a 
log ttn = — 2,980 — 2 
) 
and 
1) KUENEN, |. c. 
3) Comp. VAN DER Waats, Contin. I, p. 158. 
