FEVERS. 585 



ity, where it is small and frequent, especially where it is fre- 

 quent upon the smallest motion, and where at the same time it 

 is laborious. But the matter is ambiguous, because these same 

 symptoms are often only marks of obstruction in the vessels of 

 the lungs, which gives a resistance to the transmission of the 

 blood ; but where they are without any other symptoms of that 

 obstruction or resistance, they are to be considered as marks of 

 debility. How debility will produce them is I think obvious : 

 A small respiration occurs when the muscles which perform it 

 are weaker ; but if the inspiration for one moment be smaller 

 than it ought to be, transmitting a less quantity of blood through 

 the lungs, then, in order to compensate that, either the exer- 

 tion of a vis medicatrix naturae, or the stimulus of that accu- 

 mulation will immediately produce a more frequent inspiration. 

 And though I have said that a laborious breathing is especially 

 an attendant on an obstruction in the lungs, it will especially 

 occur when the ordinary muscles of inspiration are weak. We 

 observe that the breathing is laborious, when not only the dia- 

 phragm, which is chiefly employed in that function, is exert- 

 ed, but when the intercostal muscles are likewise considerably 

 employed ; but not only the ordinary intercostal muscles, but 

 all those which lie between the clavicle and scapula, and be- 

 tween the vertebrae and ribs, and farther, the muscles that give 

 a fixed point to them, those extending the head and neck, are 

 exerted. This constitutes the Respiratio sublimis of patholo- 

 gists, and it occurs more frequently as a mark of debility than 

 as a mark of resistance to the transmission of the blood. The 

 two states, however, may occur together, the weakness ap- 

 pearing first, but the accumulation which it occasions amount- 

 ing to a state of obstruction. Dr. Boerhaave's saying, therefore, 

 that almost every person dies of a peripneumony, amounts to 

 little more than this, that every body dies for want of breath. It 

 is very likely that before death happens, the accumulation of 

 the blood in the lungs, in consequence of this weaker respira- 

 tion, concurs as one of the means of putting a final end to life; 

 but it would be improper to say that this was a peripneumony, 

 though the weakness may be sometimes of the peripneumonic 

 kind, or may approach to the peripneumonic degree. 



" While we are uncertain in interpreting the state of the re- 

 VOL. i. 2 T 



