T.HE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FIFTH SERIES.] 



OCTOBER 1884. 



XXXII. On the Chemical Combination of Gases. By J. J. 

 Thomson, M.A., F.R.S., Fellow and Assistant Tutor of 

 Trinity College, Cambridge* . 



THE view of chemical combination taken by Clausius and 

 Williamson, which, as is well known, is that the atoms 

 which form the molecules of a compound gas are continually 

 changing partners, possesses many advantages. One of these 

 is that its consequences can be developed by mathematical 

 analysis, and that without any further hypotheses many im- 

 portant results may be deduced. The following paper is an 

 attempt to develop mathematically some of these conse- 

 quences ; particularly those which concern the effects of 

 time, pressure, the quantities of the combining bodies present, 

 and the temperature upon the results of the chemical com- 

 bination. It can, I think, hardly be doubted that the effects 

 of these circumstances on chemical combination have been 

 too much neglected by chemists, and that one of the reasons 

 why we know so little about chemical affinity is that chemists 

 have confined themselves to studying the ultimate effects of 

 any combination, and have neglected the changes which 

 take place whilst the combination is still going on. To take 

 a quite analogous case, the science of biology would not be 

 in its present satisfactory condition if the biologists had 

 entirely confined their attention to full-grown animals and 

 had altogether neglected the study of embryology. Of late 

 years, however, more attention has been paid by chemists to 

 * Communicated by the Author. 

 Phil. Mag. S. 5. Vol. 18. No. 113. Oct. 1884. R 



