< 472 ) 

 be calculated perfect!}' accurately from 



3»? 

 /; — V —- = r log (v — 2 b etc.) 



dv 



Approximativoly thers is equality, but I have not succeeded in 

 proving that the entropy of Prof. Boltzmann is really identical 

 with the quantity rj of this relation. 



These considerations have suggested the question to me, whether 

 the problem, the accurate solution of which Prof. Boltzmann gives, 

 might be the following: In what way do a great number of moving 

 material points arrange themselves, when they are subjected to an 



attractive force, which leads to a surface pressure —;■ , when they 



cannot come nearer to each other than at a certain distance (dia- 

 meter of a molecule). If they are really material points, the work 

 of the thermic pressure does not exist — and Prof. Boltzmann's 

 equation for coexisting phases might be defended. But then the 

 real problem, how do molecules with dimensions arrange themselves, 

 remains unsolved. 



But then ther e woul d be no reason to be astonished, that there 

 is no perfect agreement in the results. I am sooner astonished that 

 the agreement is as great as it is. 



For a full discussion it would of course be necessary to compare 

 also other equations of Prof. Boltzmann with those I have deduced. 

 Only if this were done it would be possible to make clear the 

 difference in the nature of our views. This would be specially 

 desirable for the calculation in first approximation of the influence 

 óf the molecular dimensions on the value of the pressure. I.e. p. 7 

 etc. Here too, the result at which we arrive' is only equal at a 

 first approximation, without the results being identical. 



And the question presents itself, whether the problem which is 

 treated in Boltzmann's „Vorlesungen", might be formulated still 

 more accurately than has been done above, by saying: A great 

 number of moving material points move in spaces which are dimi- 

 nished by eight times the molecular volume — a conception, accor- 

 ding to which the material points would move in a space, which 

 would lie outside the distance spheres, which they themselves form. 



It is indeed remarkable that Prof. Boltzmann succeeds in pre- 

 venting that in this way he would find an influence on the pressure 

 wbJQh. is -twice too large. By ^T,ssuming a perfectly flat wall, and 

 ^y.;,,U_siiig , this wall as a means, to eliminate the;distance spheres 



