Analyjis of the Jir. 269 



is but y ' T part of the depth of what is per- 

 fpired off the furface of a man's body in that 

 time. 



If then life can by this means be fupported 

 for five minutes with four Diaphragms and 

 a gallon of air, then doubtlefs, with double 

 that quantity of air and eight Diaphragms, 

 we might well expect: to live at lead ten mi- 

 nutes. It was a confiderable difadvantage, 

 that I was obliged to make ufe of bladders, 

 which had been often wetted and dried, fo 

 that the unfavoury fumes from them muft 

 needs have contributed much to the unfitting 

 the included air for refpiration : Yet there 

 is a necefiity for making ufe of either blad- 

 der or leather in thefe cafes ; for we cannot 

 breathe to and fro the air of a veffel, whofe 

 fides will not dilate and contract in confor- 

 mity with the expirations and infpirations, 

 unlefs the vefTel be very large, and too big 

 to be conveniently portable. 



Having flopped up the wide fucking ori- 

 fice of a large pair of kitchen bellows, they 

 being firft dilated, I could breathe to and fro 

 at their nofe, the air contained in them for 

 more than three minutes, without much in- 

 convenience, they heaving and falling very 

 ealily by the action of refpiration. Some 



fuch- 



