C 577 ] 
and fhall only add here, that in the cafes above re- 
cited, where the quick pulfe and feverifhnefs pro- 
ceeded more from a pituitous infarction than a true 
inflammation of the lungs, bliflers, by relieving this 
organ, in fome meafure, of the load of humours op- 
prefling it, would render the circulation through its 
veflels freer, and confequently leflen the quicknefs 
of the pulfe, and other feverifli fymptoms. 
It may not, however, be improper briefly to point 
out the reafon, why bliflers, which have been ob- 
ferved to be remarkably efficacious, even when early 
applied, in pleurifies (3), are lefs fo in true peripneu- 
monies. This difference, I imagine, may be ac- 
counted for from there being no immediate com- 
munication between the pulmonary veflels and thofe 
of the fides and back, to which the bliflers are ap- 
plied j whereas the pleura , and intercoftal mufcles, 
are furnifhed with blood-veflels from the intercoftal 
arteries, which alfo fupply the teguments of the 
thorax : fo that while a greater flow of ferous hu- 
mours, and alfo indeed of red blood, is derived into 
the veflels of the external parts, to which the vefica- 
tories are applied, the force of the fluids in the vef- 
fels of the inflamed pleura , or intercoftal mufcles, 
muft be confiderably leflened. Further, as the in- 
tercoftal mufcles and pleura are, as well as the tegu- 
ments of the thorax , fupplied with nerves from the 
true intercoftals, bliflers applied to the back and fides 
may perhaps, on this account alfo, have a greater effeCt 
in relieving inflammations there than in the lungs, 
(3) Dr. Pringle’s Gbfervations on the Difeafes of the Army, 
part iii. chap. 2. 
Vol, 50. 4E which 
