[ 339 ] 
arc however fome examples [i], where It has been 
hurtful. It is urged further, that a perfon, being 
only for a fliort time expofed to really putrid exha- 
lations, may be infedled with putrid difeafes ; and 
therefore that this elFedlof putrid exhalations does not 
depend on the volatile alcali, as it may be taken pure 
in very large dofes, without producing fuch effeds. > 
To this I reply, by an analogous inftance ; a fmali 
quantity of ferment will bring on fermentation in a 
large mafs of fermentable matter, and yet as much acid 
as could be obtained from the ferment, far from 
exciting an inteftine 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 caufe of fetting the whole mafs in fermentation? 
In the fame way, the alcali combined with phlogiftic 
matter may produce fuch inteftine motion as the 
pure alcali cannot ; and very likely the firft would 
not produce it, if the volatile alcali in it could be 
changed. 
To bring this about, the moft powerful means feem 
to be the ufe of acids; and the moft celebrated 
phyficians agree in the good elfedt they have 
obferved from acids in putrid difeafes, and re- 
commend them flrongly. Dr. M ‘Bride thinks o- 
therwife, and his reafons are thefe : Ji7'Jl that 
if the acids came unchanged to the abforbent 
vefTels, they would not admit of them [k]-, Jeco?idl)\ 
[/j Huxham on the fore throat, p. 67, 68. Ejufci. ElTay on 
feveis, p. 1 18, edit. 5. 
[i] Experiment Eflays, edit. fee. p. 20. The avitlere acid 
(generated in the firft pafiages of wealdy perfons) is cxacUy in 
the fame ftate with a foreign acid, for the lactcals will adirfic 
none of it. 
X X 2 
if 
