was formed by the human skin, wheresoever the ex- 
ternal surface of the living body came into contact 
with atmospheric air ; but, in all the experiments 
made to establish this point, sources of fallacy, which 
render the opinion somewhat doubtful, maybe point- 
ed out. In De Milly's experiments, the water in 
which the body was bathed might afford carbonic 
acid, as Priestley (148.) and others remarked. In 
Mr Cruickshank's experiments, the hand and foot 
were confined in a vessd covered over with a mois- 
tened bladder ; but this bladder, as Dr Klapp ob- 
served, might furnish carbon to unite with the oxy- 
gen gas of the air, and thus give rise to the produc- 
tion of carbonic acid *. The vitiation of the air in 
bottles fastened to different parts of the body, as re- 
ported by M. Jurine (147.) , did not take place in si- 
milar experiments made by Dr Priestley f ; and the 
carbonic acid, found by the same author, in the air 
confined under the bed-clothes, where different per- 
sons had slept, might, as M. Seguin remarked, pro- 
ceed directly from the lungs. Lastly, the experi- 
ments of Mr Abernethy, who supposed both an ab- 
sorption and transpiration of aeriform fluids to be 
carried on b^the skin, are contradicted, in all their 
results, by the later and more accurate trials of Dr 
Klapp (150.), who found that no emanation of gas 
took place from the skin, when the hand was con- 
fined for several hours in hydrogen gas, in mercury, 
or in lime-water^ 
* On i.he Functions of the Skin, p. 14. 
f Obs. on Air, t p ol. iv, p. 275. 
