MEMOIRS 



OF THE 



LITERARY AND PHILOSOPHICAL SOCIETY 

 OF MANCHESTER. 



I. On the Composition of the Atmosphere. By R. Angus 

 Smith, Ph.D., F.R.S., F.C.S., President of the Society. 



E>ead November 15th, 1864. 



In this paper I have given, first, the inquiry into the 

 composition of the atmosphere contained in a report to 

 the Royal Mines Commission; and secondly, a subse- 

 quent inquiry, chiefly relating to specimens taken from 

 various parts of Scotltod, but including some from other 

 countries. 



When it was found necessary to compare the air of 

 mines with the standard atmosphere, I found that, although 

 I had read on the subject, I was unable to tell the composi- 

 tion of the air with great certainty and exactness. After 

 examining many analyses, I came to the conclusion that 

 the mean of Regnault's Paris analyses gave the oxygen 

 very correctly as 20*96 ; and, after examining many speci- 

 mens, I still consider that as a fair mean. But, lest this 

 should be disputed, I took 20*9 as the number, which 



SER. III. VOL. III. B 



