S02 ESSAYS AND OBSERVATIONS 



mulated in the pulmonary vefTels. And 

 to this it is owing, that refpiration is not 

 only flower, but fomewhat deeper in 

 time of fleep, than in a waking perfon at 

 reft in a horizontal pofition. 



In comatous and apopledic cafes, 

 where all the feelings of the body are 

 much more impaired than in ordinary 

 fleep, refpiration is not only much flower 

 and deeper than ufual, but fometimes, 

 ^fter expiration is flniflied, a paufe of 

 15, 20, 30, or more feconds will inter- 

 vene, before a new infpiration is begun. 

 Much the fame thing happens to animals 

 who have fwallowed too great a quantity 

 of opium *. 



Now, if it be reafonable to afcribe the 

 flow, deep, and interrupted breathing, in 

 fuch cafes, to the infenfibility which at- 

 tends thofe '^ difeafes of the head; and 

 which opium never fails to produce, when 

 taken too liberally ; are we not hence led 

 to conclude the lefs remarkable change of 

 breathing which happens in fleep, to be 



owing 



♦ Eflay on the vital and involuntary motions, &c. 

 p. J 94. 



