Refpiration , and the Ufe of the Blood . 233 
•probable, that this' air ferves as a cement to bind the 
earthy parts together. He alfo makes no doubt, but that 
various other matters, mifcible with water, are inhaled 
bj the lungs ; and he even thinks it not improbable, that 
the air may carry fome electric virtue along with it. The 
principal exhalation of the lungs, he thinks, to be water, 
abounding with oily, volatile, and faline principles ; and 
thefe oily and fetid vapours, he thinks, to be the fuligines 
of galen and other ancients, p. 354. 
Mr. cigna of Turin, has given much attention to this 
curious fubjeft, as appears by two Memoirs of hist one 
in the firft volume of the Mifcellanea Taurinenfia, in which 
he very well accounts for the florid red colour of the 
blood; and the other, which is a much more elaborate 
Memoir, intitled, DeRefpiratione , in the fifth volume of the 
fame work, juft publifhed, or about to be publifhed, the 
copy of the article having been fent to me by the author. 
He takes it for granted, that air which has once been 
breathed is unfit for farther refpiration, on no other ac- 
count than its being loaded with noxious vapours , which 
difcover themfelves by a fetid fmell. Mifc. Taurin. vol. 
V. p. 30. And he takes it for granted, that the elafticity 
of air is diminifhed by refpiration, though he does not 
confider that diminution of elafticity as the caufe of its 
noxious quality. He therefore concludes, that air which 
has been breathed, fuffocates by means of the irritation 
which it occaftons to the lungs, by which the bronchia, 
and the lungs themfelves, are contracted, fo as to reftft the 
entrance of the air; and therefore, that refpired air is 
Vol, LXVI. H h noxious 
