148 © Dr. Mitchill’s Ob/ervations on Pot-Afh, 
miftake, and which nearly deprived a man of his life. Afet q 
of correct experiments is wanting to clucidate more com- : 
pletely this part of a very curious ‘and highly important fub- — 
ject. 
Be thefe things as they may, all experience fhews that the 
connexion between feptic acid and pot-afh is eafy to diffolve 5 
at leaft, a portion of oxy oo feparates very readily from the 
hitre. The experiment of reddening blood by mixing ‘pow- 
dered fat rtpetre with it, was known to Hoffman, and, I think, 
fairly evinces a partial decompofition of the falt. It feems to 
have a fimilar operation upon the refidue of that fluid in the 
flefh of flaughtered animals, and the reddening of the Jean © 
and fibrous part of meat is rit a owing fo the oxygen — 
attracted from the nitre. ; 
But a heightening of colour is not the only effect which — 
feptite of pot-afh works upon provifions fprinkled with it. ~ 
There are in many meats, efpecially of old animals, and of j 
thofe which have been a long time falted, a foughne/s and — 
bardnefs which render them difficult to be cut and to be — 
chewed. The feptic acid feems in fome degree to be dif- 
joined from the pot-afh, and evidently affifts in decompofing, — 
to a certain point, fhe vafcular and fibrous ftru€ture of the’ 
meat, The quantity of nitre generally put on is fmall; was 
the proportion ‘larget, the meat would be yet further difvad q 
ganifed, and be feared more /hort and tender, almoft even 
to rottenne/s. But the injurious effect of the nitre is pre=_ 
vented by the fea-falt commonly mingled with it, in the — 
manner and upon the principle defcribed in my “ Obferva-_ 
tions on Soda.” (2 Medical Repofitory, p. 292, et /eq.) The 
ufe of faltpetre, then, in curing provifions, 1s to make thenr 
reddifh and tender, and not to exercife an antifeptic and bard=~ 
ening power, as the muriate of foda does, r 
/With all thefe confiderations before me, I entertained” 
great doubts of the truth of thofe fine things told over and” 
‘mildnefs and wholefomenefs of nitre, and of its wonderful — 
effe&ts as a calmer and foother of difeafes. It feemed very | 
range to me, that the ua which before its union via 
