VOL. LXI.] PHILOSOPHICAL TRANSACTIONS. I67 



ment, far from exciting an intestine motion in the fermentable matter, would 

 rather check, it ; but can it for all that be denied, that the involved acid in the 

 ferment is the chief cause of setting the whole mass in fermentation ? In the same 

 way, the alkali combined with phlogistic matter may produce such intestine mo- 

 tion as the pure alkali cannot ; and very likely the first would not produce it, if 

 the volatile alkali in it could be changed. 



To bring this about, the most powerful means seem to be the use of acids ; 

 and the most celebrated physicians agree in the good effect they have observed 

 from acids in putrid diseases, and recommended them strongly. Dr. M'Bride 

 thinks otherwise, and his reasons are these: first that if the acids came unchanged 

 to the absorbent vessels, they would not admit of them ;* 2dly, if they did, they 

 would be dangerous ;-|- and 3dly that they are quite changed, before they leave 

 the primae viae. ^ As for the first, I do not know what reasons Dr. M'Bride 

 founds his assertions on, as acids never are given in so concentric a state, as by 

 their astringency to make these vessels shut up their orifice ; and as metallic 

 salts themselves are absorbed in their very compound state (which seems clear 

 with regard to the corrosive sublimate, and other such saline preparations), I do 

 not see why the simple acids could not be absorbed. The 2d reason seems to be 

 founded on some of Dr. M'Bride's experiments (p. 132, 133), viz. that putrid 

 flesh, sweetened by distilled vinegar and spirit of vitriol, was firm; but on 

 being boiled went quite to pieces, whereas that sweetened by volatile alkali did 

 not. But I conceive these experiments are not applicable to a living body : for 

 the acid being there mixed with the fluids, cannot act in this way on the solids, 

 till the fluids are (if I may use that expression) supra-saturated with the acid, ^ 

 which in putrid diseases cannot be the case. And further, a heat of 212° of 

 Fahrenheit never can iticrease the action of the acids in living bodies, as it did 

 in the experiments ; for though Dr. M'Bride denies this consequence, and will 

 prove the contrary, as the flesh with the alkali did not dissolve ; yet this circum- 



* Experimental Essays, edit. sec. p. 20. The austere acid (generated in the first passages of 

 weakly persons) is exactly in the same state with a foreign acid, for the lacteals will admit none of 

 it.— Orig. 



+ Ibid. p. 13-t, the acids dissolve the elementary earth, and thus destroy the texture of that sound- 

 dessthey are supposed to restore. — P. 148, we are not to expect that they are to pervade the minute 

 branches of the vascular system} when indeed it is evident, that they ought not to be allowed to pass 

 into the blood in their acid form; since it is plain, that from their dissolvent nature, the body must 

 be destroyed, and its most solid parts melted down to a jelly, if naked acids were to be received into 

 the general mass of fluids. — Orig. 



X Ibid. p. 148, acids are neutralized during the alimentary fermentation; and therefore they can- 

 not act as acids, by saturating any thing of the alkaline kind that they meet with in their course Of 

 circulation. — Orig. 



§ This has, it seems, happened in some rare cases quoted by Dr. M'Bride, and Dr. Haller, p. 

 148.— Otig. 



