[ 3*8 ] 
with the nitrous acid and chalk, and alfo common 
fair, digeftive fait of Sylvius, and a fait made with 
vinegar and the fofiil alkali. Thefe experiments 
were fufficient to convince me, that this property 
was very general among thofe falts which confift of 
acid and alkali ; and therefore it feemed unneceflary 
to profecute this enquiry farther *. 
But acids and alkalies have different effects on 
thefe veficles from what neutral falts have. 
The fixed vegetable alkali, and the volatile al- 
kali, were tried in a pretty ffrong folution, and 
found to corrugate the veficles r and in proportion 
as they were diluted, their effects became fimilar 
to water alone, but it is not eafy to find the point 
of ftrength where the veficles would remain unal- 
tered in the lolution. And here we may obferve, 
that fince thefe veficles are found to difiolve fo 
readily in water, and not to be diffolved in thefe 
folutions of alkali, it is a ffrong argument againfl 
their being either oily or faponaceous, as they have 
been fufpeftcd. 
The effedls of acids are very different. I have 
tried the vitriolic, nitrous, muriatic diftilled vine- 
gar, and the acid of phofphorus ; thefe, when much 
diluted, have the fame effects as water in making 
the veficles fpherical and, in proportion as they 
are lefs diluted, they difiolve the veficles without 
making them fpherical, as water does. I never 
* Thefe experiments were made by putting one drop of the 
fiturated folution of the fait into a tea cup, and then adding dif- 
tilled water by a few- drops at a time ; and to this mixture the 
ferum of the blood, highly tinged with the red veficles, was 
added. 
could 
