( 536 ) 
inter alia van der Waals, Cant. II p. 190 (1900)]. Only at tempe¬ 
ratures higher than T 0 .. . there can be question of homogeneity to 
the highest pressures.” 
It seems to me that every unprejudiced reader of these lines 
must acknowledge that Mr. van Laar thought that he gave a new 
result here, materially ditfering from the result of a closed plait as 
it was thought possible by van der Waals, and that he cannot 
possibly have realized when writing these lines that this divergent 
result was only founded on his assumption — = 0. 
3. As to point c, the sentence mentioned there really refers to a 
paper by Mr. van Laar earlier than April 1905 (viz. of January 1905). 
I did not know, however, until the publication of the “Remarks”, 
(and now I only know it from these “Remarks”) that Mr. van Laar 
has abandoned his views of this previous paper. Else we should, 
of course, not have mentioned it. 
4. With regard to point d we must protect Mr. van Laar against 
himself. We had said: “His results are of importance particularly 
because they showed that under certain circumstances non-miscibility 
can occur for perfectly normal substances, a fact which was generally 
doubted at the time.” Mr. van Laar remarks in this connection that 
it was by no means generally doubted up to now whether miscibility 
could occur for normal substances but only whether some special 
“abnormal” forms of non-miscibility could occur for perfectly normal 
substances. I must maintain in opposition to this that both Lehfeldt 
and van der Waals, to whom we referred l.e., had by no means a special 
case of non-miscibility in view, but very decidedly all non-miscibility. 
So Mr. van Laar’s merit is decidedly greater than he will own here. 
On the other hand I must confess that in our endeavours to be 
perfectly objective to Mr. van Laar, we have really got unjust in 
the above cited sentence to Mr. van Laar’s predecessors: van der 
Waals and Korteweg. The above statement might lead one to think 
that Mr. van Laar had been the first to demonstrate the possibility 
of non-miscibility for normal substances. As Mr. van Laar justly 
remarks: this is incorrect, and it would have been better if our 
sentence had run like this: His results are of importance particularly 
because he adhered to the possibility of non-miscibility for normal 
substances in a time in which this was pretty generally doubted, 
and showed once more that for certain values of as and ft's,which 
could not a priori be considered as improbable, non-miscibility must 
really appear”. 
If I wanted to discuss also Mr. van Laar’s other remarks, I should 
