NITRO. MURIATIC ACID. 
101 
NI'TRIC, adj. Mixed or impregnated with nitre, par¬ 
taking of the nature of nitre. 
NI'TRIC A'CID. See Chemistry, vol. iv. p. 161. 
215, 238. 
NI'TRITS, f. See Chemistry, vol. iv. p. 243. 
NITRO-MURIATTC A'CID. This acid is formed 
by mixing the nitric and muriatic acids together, or by 
diflolving muriat of ammonia in nitric acid. In the latter 
procefs part of the nitric acid decompofes the fait, while 
the other part afts upon the difengaged muriatic acid, to 
form the nitro-muriatic acid. This acid was known to 
the ancients, who called it aqua regia, from its property 
of diflolving gold. It is now pretty generally admitted 
to be oxymuriatic acid , formed by the oxygen of the nitric 
acid with the muriatic acid. See Chemistry, vol. iv. 
p, 217, 218. 
This acid, compounded in different proportions, and 
diluted with water, has been lately introduced into medi¬ 
cal practice as a remedy for fyphilis and for difeafes of the 
liver. It is ufed either internally, or as a bath, or by 
fpongjng the body all over with the dilution. The modes 
•of applying it, and its effects, are very fully explained by 
Dr. H. Scott (in the Medico-Chirurg. Tranf. 1817.) who 
tried its effects repeatedly upon himfelf, and with great 
benefit. 
“ I left India (fays Dr. Scott) in very bad health, and 
long remained ill in this country. During this period I 
often reflected on my experience with the acids; and re- 
iolved, as foon as an opportunity fliould occur, to return 
to<the ufe of the nitro-muriatic acid, and to fatisfy my 
mind on the fubjeft from further obfervation. Above a 
year ago I came to London, and had an opportunity of 
getting the nitro-muriatic acid employed to a confiderable 
extent. At fir ft, I mixed three parts of nitrous acid with 
one of muriatic, in order to imitate the acid I had ufed 
in India. Of’late, however, I have employed the acids 
in.equal weights, and I give a preference to this propor¬ 
tion ; but there may be others ftill more efficacious, which 
time will difcoyer. 
“ Although I had reafon in India to be latisfied with 
the. general effects derived from this, acid, yet confider- 
abicinconvenience attended its internal ufe. If it were 
not given with great caution, it injured the enamel of 
the teeth, though not their roots as mercury does. Even 
in fimall quantities, it dilagreed with forne ltomachs; and 
few individuals indeed could continue it fufficiently long, 
or in lufficient quantity, to remove from the fyftem the 
fymptoms.of fec.ondary fyphilis. Thefe difficulties made 
me anxious to. afcertain whether or not the acid, exter¬ 
nally applied, would produce good effe&s. I accord¬ 
ingly employed it in this manner in various cafes; and I 
immerfed my own body up to the chin in a bath of this 
acid, fufficiently diluted with water. I fortunately have 
preferved the memoranda, that I made at the time, of 
which the. following is a copy. 
“ Bombay ; 27th April, 1798.—I bathed to-day in an 
acid bath, which was merely acidulous. If covered the 
whole:body below the head. I ftaid in it for half an hour, 
and it was nearly of the temperature of the body. I feel 
no particular effeft from this bath : it is fully as pleafant 
a-s water, and cleanfes the fkin like a foap. 
« April 28th. I bathed again to-day, keeping the bath 
at-the fame temperature, or making it rather higher, of 
the fame ftrength with regard to acid. I ftaid in it half 
an hour. I ftil! feel no material effeCt from the bath. 
Pulfe after bathing 76°. The only apparent action of the 
acid is on fuch animal matters as are unprotected by life, 
with which it forms an acid foap. Would it not deprive 
feathers of their oily finell r 
“ 29th. Bathed again, and continued, as before, for 
half an hour in the bath. To-day the bath was- hardly fo 
hot as the body. About half an hour after bathing vefrer- 
day, I became fenfible of'an. odd fenfation about my 
gums, my jaws, and my teeth. 
5 “ ,30th. Bathed again, and frayed half an hour in the 
bath. It was rather warmer than my body. Since yef- 
terday I have been fenfible of fome uneafinefs in my 
throat on fwallowing. I feel a difpofition to falivation at 
times : but I am otherwife well. My gums, both above 
and below, are fomewhat reddened. 
“ May ift. Since yefterday I have felt fome pain in my 
throat, efpecially on fwallowing. This pain feems to 
follow the courle of the cefophagus. During the whole 
of this forenoon I had a fenfe of burning• over the roof 
of my mouth and down the gullet. This fenfation is 
like what arife.s from having chewed an acrid vegetable 
fubftance ; and is fo unpleaf'ant, that, unlefs it leave me 
by to-morrow, I fliall bathe no more. To-day I bathed 
as ufual, fraying in the bath for half an hour. It has been 
to-day, and in general, lb acid, as to make my Ikin l’marfc 
a good deal in many places. 
“ 2d. My mouth, &c. though not in the lead ulcerated, 
is fomewhat pained. I am fufficiently convinced of the 
great power of this bath, and fliall bathe no more. My 
digeftion is improved; and I feel that my liver, unclogged 
by difeafe, is doing its office with facility, which for fome 
time pall’has not been the cafe with me. 
“ June 61I1. For a fortnight after giving up the bath, 
I was fenfible of fome of its effeCts about my mouth, and 
my pulfe remained too quick. I am now remarkably well. 
My liver feems to be found, and I have experienced a 
happier change than I ever did from mercury. 
“ When I came to London, and had it in my power 
to have the 1 nitro-muriatic bath employed for various 
ftates of difeafes, I was, as may be fuppofed, very anxious 
to known if it could be as commonly applicable in this 
climate as itis within the tropics. I have been much pleafed 
to difcover that it gives here the very fame refults that l 
formerly derived from it; nor are the maladies for which 
it may bring relief, lefs genera] in this country than in 
India. On the contrary, they feem to be Hill more abun- 
dant. 
“ The acid that I have ufed of late is formed by mixing 
together equal parts of the nitrous or nitric acid and. 
muriatic acid. If thefe acids be in the ftate of concen¬ 
tration that they ufually poflefs in the (hops, and if the 
quantifies be confiderable, a great volume of gas is evolved 
on their coming into contaCt, which taints every part of a 
lioufe, is extremely hurtful to the lungs, and difagree- 
able to the fmell. To avoid all this inconvenience, I put 
a quantity of water, at leaft equal in bulk to both the 
acids, into a bottle, and I add the acids to it feparately. 
This method does not only prevent the unpleafimt odour, 
but it tends to retain the chlorine, on which its efFedts 
depend. It is well known that the nitro-muriatic acid 
acts very readily on the metals and earth ; nothing there¬ 
fore but glafs, or extremely well-glazed vefiels of porce¬ 
lain, lhould be ufed to contain it. Wooden tubs for 
bathing anfwer very well; and they lhould always be made 
as/mall as pojjible, compatibly with their holding the 
body, or the limbs that we wifii to expofe to the bath. 
From their being final 1 , we lave acid, and are able to heat 
the bath with eafe. In India I have often expofed. the 
whole body below the head tathis bath; but here I have 
been fatisiied in genera! by keeping the legs and feet'ex- 
poied to it. In order to warm the bath after the firft, 
time, I have commonly made a third Or a fourth part of 
it be thrown away, and the lofs replaced by boiling water, 
and a proportional quantity of acid. To lave the expen¬ 
diture of acid, I have occasionally warmed a portion of 
the bath in porcelain veifels /placed near the fire; but I. 
fear this may diminilh its efteits. 
“ It is no eafy matter to give directions with regard to 
the degree of acidity of the hath. I have commonly made 
it'about asfrrongas very weak vinegar, try fling to the 
tafte alone. The frrength lhould be regulated by the de¬ 
gree of irritability of the patient’s fkin, I may lay, that, 
although I like to know that it is frrong enough to prick 
the fkin a very little, after being expofed to it from fifteen 
•to thirty minutes, yet I believe that even fuel! an effect 
as 
