4%0 Dr. Mitchill’s Obfervations on Pot-Afh, i 
tite of pot-ath (faltpetre.) This was about cleven o'clock: 
before noon, and he had taken it at fix in the morning. As 
it had had no purgative effect, I ordered him fome cate oily 
and almond milk fweetened with fugar, or fome pe thle 
ee fome water-gruel. 
35 Commentar, de Rebus, &c. p. 196, a cafe is men- 
cand of death from taking an ounce of nitre: arid if a part 
of the quantity which this mam took had not been vomited 
tip, he probably would have died too. | The ol. ricini purged 
him gently, and he gradually got better, but complained 
very much of weaknefs about the preecordia. 
There are numerous other accidents not materially unlike 
thefe. Such occurrences give us no very favourable account 
of the benignity of nitre as a medicine. It is a pity that 
practifers of phyfic do not better underftand the component 
parts of their preferiptions. How few know that, in admi- 
niftering nttre, their patients are made to fwallow a portion 
of the naufeating and fickening acid of putrefaction ! 
Poffibly thefe yemarks may have a tendency to rempove the 
doubt-contained in your letter of April 11, 1799. You will 
hereby perceive that my native acid of fepton is a combination 
of this bafis with oxygen and water ; whereas your arézficial 
acid of nitre undergoes a partial davonsiedn by the heat of 
dittillation, and is adulterated befides with whatever happens 
to be mingled with it during and after its combination with 
the vegetable fixed alkali. And both thefe forms of acid 
differ from atmofpherical air; inafmuch as the former are 
chemical mixtures, the latter is mechanical. 
It would be better for fcience if the word ‘* nitre’” was re- 
jected altogether from ufe. Nzéria, whence the term comes; 
was, you know, a diftriét of ancient Egypt, famous for the 
quantity of mineral alkali which it afforded. (D’Anyille’s 
Geograph.—Egypt.) This faline fubftance has thence been 
called by the ames mitrum, mitre, &c. En confirmation of 
which, I obferve, in the Dictionary of Calepinus, printed at 
Bafil in 1538, that what they ealled mztrwm was a material 
employed to cleanfe clothes, and wath the bodies which wore 
them. And S. Bochart remarks, (1 Opera. Chanan, L. II. 
cap. xiv.) that the ancients made a kind of ley from a/besy 
Joday 
