136 



" the greater part of the nitrogen gas (93.) be again 

 liberated unaltered," why cannot we discover some 

 traces (102.) of its existence in that fluid ? or why 

 should its presence be so rapidly fatal, as experiment 

 (1O3.) proves it to be ? 



111. But the supposed stimulant effects of this 

 oxide have been assigned as an argument for its be- 

 ing in some way contained in the blood. In many 

 cases, however, these effects do not follow the inha- 

 lation of that gas : and, in other instances, common 

 air, breathed under the impression of its being this 

 oxide, has produced them. Similar effects likewise 

 are attributed by some authors to the inhalation of 

 carbonic acid ; and Dr Percival quotes M. Beaumc 

 as relating the history of a man who was recovered 

 from apparent death, produced by exposure to the 

 foul air of a cellar, who asserted that he had felt 

 neither pain nor oppression, but that, at the point of 

 time when he was losing his senses, he experienced 

 a delightful kind of delirium. This account, adds 

 Dr Percival, receives confirmation from the testimo- 

 ny of Dr Heberden, who says, that he had seen an 

 instance in which the fumes of charcoal brought 

 on the same delirium as intoxicating vegetables pro- 

 duce. The Abbe Fontana likewise breathed a cer- 

 tain portion of hydrogen gas, not only without in- 

 convenience, but with unusual pleasure : he had a 

 facility in dilating the breast, and never felt an e- 

 qually agreeable sensation, even when he inhaled 

 the purest oxygen gas *. From these facts, it ap- 



Manchester Memoirs, vol. ii. p. 491, 492. 



