323 
of Edinburgh, Session 1873 - 74 . 
During tbe winter of that year lie took up his residence at 
Enniscrone, county Mayo, being under medical advice to give up 
active work for some months at least ; but with a strong desire to 
carry on bis chemical researches, be fitted up for himself a temporary 
laboratory there ; and be was actively engaged in prosecuting them 
at the time of bis sudden death, on the 13th of September 1872. 
His death was occasioned by an acute disease of the brain, of which 
he seems to have had a slight warning some months previously; 
but his last illness w r as not more than a few hours of intense pain. 
He was married in 1869. His wife survives him ; hut he left no 
children. 
Mr Hunter’s researches were chiefly concerned with tlfe absorp- 
tion of gases by charcoal. He examined a large number of char- 
coals, and came to the conclusion that the greatest absorptive 
power is possessed by the dense charcoal of the shell of the 
cocoa-nut. With this material he proceeded to examine the absorp- 
tion of a very large number of gases and vapours ; and he extended 
his researches to the absorption of mixed vapours. He also inves- 
tigated the relation between absorption and temperature in the 
cases of ammonia and cyanogen, and showed that, while raising 
the temperature at which the charcoal is exposed to, the gas 
decreases the absorption in both cases; the rate of decrease is much 
greater in the case of ammonia than in the case of cyanogen, 
between 0° C. and 55° C. ; but at 55° C. the rate of decrease in 
the case of ammonia suddenly diminishes, and up to 80° 0. it is 
not very much greater than the rate of decrease for cyanogen. At a 
point a little higher than 55° the volumes absorbed are the same for 
the two gases. Above this point more of cyanogen gas is absorbed 
by a given weight of charcoal than of ammonia; but below that 
point ammonia is enormously more absorbed than cyanogen. Mr 
Hunter was extending his observations to the effect of pressure on 
absorption. He had already published two papers on the subject. 
The last of these was communicated to the Chemical Society of 
London only a few weeks before his death ; and it is in fact 
scarcely complete, through wanting his final corrections in type 
on it. 
Mr Hunter accompanied the Deep Sea Dredging Expedition in 
H.M.S. “Porcupine” in the autumn of 1869, and published two 
2 T 
VOL. VIII. 
