On the other hand a few minor questions are extensively discussed 
in the answer, viz. the question a 13 a x a 2 and — = 0. I must 
dw* 
remark here that when I repeatedly spoke of the “quite general” 
case a t ^ a r , b 3 ^b X) this expression “quite general” was obviously 
meant in contrast to the special case a 3 ^ a 1 , b 3 — b x , treated by 
me before in the first two Papers, as would be clear to everybody, 
and that the “generality” meant by me according to the whole tenour 
of my papers, of course, only holds within the area of the once 
assumed supposition a 13 = Va x a 3 (Berthelot’s). For this supposition 
I explicitly premised in all my papers, and I repeated it more than 
once (loc. cit.). 
Now with regard to the question itself of the supposition a Xi = | /~afa t 
(which, however, is not the point at issue), I may be allowed to 
remind Mr. K. of a paper of his in the Zeitschr. f. physik. Ch. 36 
p. 41 (1901), where it, inter alia, says at the end (p. 62): “So weit 
ich aus dem mir bekannten Material zu schlieszen vermag, scheinen 
mir jedoch die Tatsachen sehr zu Gunsten der (BERTHELOT’sche) 
Annahme zu sprechen....” [ will add that I, too, consider the 
supposition a l3 = V / a x a 3 as very probable, and that seeming deviations 
from this supposition are attributed by me to the formation of com¬ 
pounds. But I hope to treat this more fully on a later occasion. 
I now demonstrated that even on this simple supposition the ab¬ 
normal type III can occur for perfectly normal substances. And this 
Mr. K. denied — as my later papers on this subject in which this 
was proved by me, had evidently escaped his notice. 
With regard to the supposition ^ = 0, Mr. K. refers to my state¬ 
ment that “qualitatively everything will remain the same if b is not 
assumed independent of * and T”. This, however, is quite beside 
the question whether the supposition ^ = 0 is of influence on my 
results or not; for v and T are not the same thing as *. I fully 
maintain my contention, and Mr. K. will, no doubt, understand, 
that this dependence on v and T was only mentioned by me, because 
van der Waals later investigations have shown that b still depends 
on this quantity. But this is not the point in question 
I, however, readily ^knowledge that when writing the lines 
about the longitudinal plait closing again, quoted by Mr K I did 
