141 
1888.] Prof. Tail’s Beply to Prof. Boltzmann, 
place to this Society. The time I can spare for such work at this 
period of the year is very scant, and Prof. Boltzmann has raised a 
multitude of questions. I will take them in order. But I must 
commence by saying, with reference to Prof. Boltzmann’s peculiar 
remarks on my behaviour as a critic, that, while leaving them to 
the judgment of readers, I shall have to bring before the same 
readers several instances in which Prof. Boltzmann has completely 
misstated the contents or the objects of my papers. This is not 
a new departure. In his first attack on me he said that I had 
nowhere stated that my investigations were confined to hard 
spherical particles ; whereas I had been particularly explicit on that 
very point. But fresh cases of a similar character abound in this 
new attack. 
First. There runs through this paper an undercurrent, at least, of 
accusation against me for putting forward my results as new, and 
thus ignoring the work of others. I had no such intention, and I 
do not think anything I have said can bear such a construction. 
My knowledge of the later history of the subject is no doubt now 
considerably greater than it was about two years ago when, at 
Sir W. Thomson’s request, I undertook an examination of Clerk- 
Maxwell’s first proof of his own Theorem. But it is still of a very 
fragmentary character. I had, years ago, read papers by Maxwell 
and by Clausius ; and had glanced at the treatises of 0. E, Meyer 
and Watson. I had also made a collection of various papers by 
Prof. Boltzmann. But I found that, without much expenditure 
of time and labour, it would be impossible to master the contents 
of the three last-named works, mainly because the methods em- 
ployed seemed to me altogether unnecessarily intricate. [I have 
already stated the impression produced on me by such of Prof, 
Boltzmann’s papers as I have tried to read, and I need not recur 
to it.] I therefore set to work for myself, having certain definite 
asserted results in view, but little knowledge of the processes which 
their discoverers or propounders had used. After obtaining a 
demonstration of Clerk-Maxwell’s Theorem, I was led to pursue my 
investigations into other matters, such as the rate of restoration of 
the special state, the size of molecules, &c, I brought before the 
Society such of these investigations as I had more fully developed; 
and I hope to communicate others, One object which I tried to 
