[ 146 J 
YI. Obfervations on Pot-afh; being an Inquiry how far the — 
mifchievous Effeéts of Septic Acid are reftrained by Pot-afh — 
and other Alkalies, particularly in refpeét to the Effedis — 
of Septite of Pot-a/b (Nitre or Saltpetre) upon Animal 
Flefh intended to be eaten, and upon the Human Stomach; 
in a Letter from Dr. Mitchill to Dr. Priefiley, dated ~ 
Plandomz, May 4, 1799; Communicated by Dr, M1tT~ © 
CHILL, 
Ox a former occafion (2 Medical Repofitory, p. 236 ef 
__feq.) an attempt was made to fhew that the /epéic acid, which ~ 
‘is formed in certain putrefactive procefles, was materially dif- 
ferent in its conftitution and qualities from the xitrous acid 
obtained by diftillation from faltpetre. Since the compofi- 
tion of that piece, I have obferved that Juncker, in his view | 
of the doétrines of Beccher and Stahl], (2 Confpeétus Chimie, 
p. 280,) is of the fame opinion, declaring, that in whatever 
manner the work of feparating it from the putrefcent or 
other bodies with which it was naturally mingled, was un- © 
dertaken, ‘ ne micula tamen acidi nitrof pure fiftitur,” zo¢ 
@ particle of pure nitrous acid can be obtained. And he warns 
his reader, that in the cbfervations which he offers he means ° 
that /pirit of nitre ONLY which is liberated from its connec- © 
tion with an alkaline falt. On the native feptic acid, which ~ 
is, as he allows, furnifhed fo largely by the animal kingdom, 
(p. 277,) and js by far the moft active and interefting form 
of oxygenated fepton, Juncker, like mott other writers, hag 
faid {carcely any thing at all. 
The highly deftrijctive effets of this offspring of putreface — 
tion have been pointed out in detail in a former eflay (t Me- © 
ical Repofitory, p. 39, 40), in which it was obferved that 
certain fubftances, and among others pot-afh in particular, 
poffeffed a power to reftrain and curb its ferocity. The neu-- 
tral falt, formed by the union of this peftilential acid with — 
the fixed alkali, is the faltpetre or nitre of the ihops and of 
commerce. Concerning the medicinal and economical qua- 
jities of this fubftance, it: is manifeft to me that there are — 
many miftakes yet prevalent : : and they appear | to be worthy 
pf being pointed out and corregted, Ts 
ng 
