364 Literary and Philosophical Society. 



Absorption of Gases by Charcoal. Part II. On a new 

 Series of Equivalents or Molecules. By R. Angus 

 Smith, Ph.D. y F.R.S. Received January 30, 1879. 



(Abstract.) 



' In the " Transactions of the British Association," 1868, 

 Norwich, on page 64 of the " Abstracts," there is a pre- 

 liminary notice of an investigation into the amount of 

 certain gases absorbed by charcoal. . . . The results given 

 were : 



Hydrogen ....... I 



Oxygen 7-99 



Carbonic oxide ...... 6*03 



Carbonic acid . . . . . .22*05 



Marsh-gas ....... 10*01 



Nitrous oxide ...... 12*90 



Sulphurous acid . . . . . . 36*95 



Nitrogen ....... 4*27 



' It was remarked that the number for nitrogen was 

 probably too low; I had some belief that the charcoal 

 retained a certain amount which I had not been able to 

 estimate. 



* For common air, the number 40*065 crept into the 

 paper or abstract instead of the quotient 7'o6. 



' The cause of this was clear, as I believed, namely, the 

 irregular character of the charcoal with which I had to 

 deal. The experiments which I had published were for- 

 gotten, I suppose, by most men, but the late Professor 

 Graham told me that he had repeated them with the same 

 results which I had given. I might have considered this 

 sufficient, but waited for time to make a still more elabo- 

 rate investigation of the subject and to take special care 

 with oxygen, in the belief that, the rule being found, the 

 rest of the inquiry would be easy ; this was extended to 



