414 
point the greatest differences can reach 16°/,, at the meltingpoints 
in some cases even 58°/, of this mean value. In every case the 
rule holds at the boilingpoint evidently much better than at the 
meltingpoint, — which could be expected beforehand. In group II 
we find: water, the alcools, the acids, and a number of aliphatic 
amines, — all substances for which association is also very probable 
as concluded from other phenomena. In group III we find i.a. the 
neutral glycerides of the fatty acids; it is very difficult to give a 
sufficient explanation for the very bigh values Ko in these cases, 
but it seems that the extremely great molecular weights of these 
compounds play a certain role in the results of the calculations. 
Abnormally small however, and without any regularity, are the 
values for A, in the ease of the molten inorganic salts; in this 
respect it is worth attention, that in the series of the alcali-halo- 
genides, Am seems to increase in general with increasing atomic 
weight of the halogen. These inorganic salts are thus evidently to 
be grouped apart, and they are certainly deviating further from the 
organic liquids, than e.g. such is the case with the halogenides of 
P and As. 
F | 0.66 | 0.70 0.78 | 1.02 | 0.96 
Ci | 0.89.) 0.81 | 0.93 | 1.13 | 1.20 
Br 410.92 | 1.01 | 1.401 1227 
1 OUP 08 14 A8 -ASBANIEISSG 
Generally speaking, we can thus say that in by far the greatest 
number of organic compounds, the empirical rules of WarpeN are 
confirmed by experiment, and that the mean value at the meltingpoint 
is very closely three times that at the boilingpoint. However it may 
appear doubtful, if it is right to conclude about the degree of asso- 
ciation of these liquids, from the deviations, which are observed 
with respect to the adopted mean values. 
Laboratory for Inorganic and 
Physical Chemistry of the University. 
Groningen, Holland, June 1916. 
