10S PHILOSOPHICAL TRANSACTIONS. [aNNO 1771. 



.stance proves nothing more, than that the volatile alkali has not such [XJwer of 

 dissolving the gluten of animal fibres as acids have; for if the effect depended 

 only on the action of the acids by themselves, the flesh would rather have been 

 dissolved when immersed in them, than when boiled in water. The doctor 

 besides seems not quite consistent on this head; for, p. 151, he says, ' Adstrin- 

 gents can only be of importance in those cases, where, from extreme relaxation 

 and resolution of the solids, the dissolved fluids are sufi'ered to transude, and 

 either form spots of different hues, or run ofi^ by actual haemorrhage ; here in- 

 deed the acid of vitriol, as an astringent, not as an acid, is found of great use in 

 gaining time.' As the acid could not exert its astringent power on the vessels, 

 without coming to the secundae viae (p. 153), he seems not afraid, in this case, 

 of its melting down the most solid parts to a jelly. 



In proof of his 3d reason, he alleges some experiments ; viz. the 3d, p. 40, 

 where a mixture of flesh, bread, lemon-juice, and saliva, did not effervesce, after 

 fermentation with an alkali ; and the 5th, p. 42, where a mixture of bread, 

 water, saliva, and spirit of vitriol effervesced smartly, before the intestine mo- 

 tion ; but not at all after it. I could object against these experiments, and 

 especially the 5th, that perhaps the proportion of the saliva to the acid was too 

 great, and that a person in a putrid disease ought to take more acids than could 

 be neutralized by the inquiline liquors. However, I will not insist on this ; and 

 suppose these experiment^ to be quite applicable to the case : but if these mix- 

 tures do not effervesce any more, does it follow, ' that they are neutralized, and 

 therefore act as acids, by saturating any thing of the alkaline kind, that they 

 meet with in their course of circulation ?' There are some saline bodies, which 

 do not effervesce when mixed together ; which will however change each other's 

 nature. Thus f. e. brimstone, mixed with a strong fixed alkali, does not effer- 

 vesce,* but changes, on being dissolved, the nature of the alkali. A solution 

 of soap does not effervesce on the addition of an acid, but joins with the acid, 

 and neutralizes it. These instances made me suspect the conclusion drawn by 

 Dr. M'Bride from his experiments; and to clear up these doubts, in this parti- 

 cular case, I referred to experiments. For this purpose, the 4th of August, the 

 thermometer being at 64°, I mixed 3 oz. of saliva, a dram of the liquor of putrid 

 flesh, and a very small quantity of bread : and added as much of the diluted 

 spirit of vitriol, as to make it sour, and effervesce definitely with the alkali. 

 There was not any sign of intestine motion till the 7th of August, when from 

 time to time some air-bubbles, and also some solid particles, rose to the top ; and 

 this continued till the 8th. Not perceiving any further motion, I poured off" the 



• This applies also to the solution of brimstone in lime-water, out of which the lime particles have 

 been precipitated, by the introduction of fixed air. — Orig. 



