2iS CHE M 
It is lighter than the two acids of which it is coinpofed; 
and it has a fmell peculiar to itfelf; its colour is com¬ 
monly that of a lemon, but fometimes,of an orange; by 
contact with light, oxygen gas is difengaged from it ; 
caloric i'eparates from it oxygenated muriatic acid ; it 
combines with water, and becomes heated in it. It would 
feem natural to conclude, that.the muriatic acid would 
have more affinity with oxygen than nitrous gas would 
have;' but by the inverfe experiment, that is, by mixing 
gas, or nitrous oxyd, with oxygenated muriatic acid gas, 
the contrary will loon appear; for, while thefe gafes are 
in contact, they penetrate each other, lofe their elafticity, 
and give, birth to red vapours, which are true nitrous 
acids. If the proper quantities be ufed, not an atom of 
refidue will be found. Hence it is only by the help of 
a double attraction, that muriatic acid can decompole 
the nitric ; namely, that of the oxygen for the muriatic 
acid, and that of the nitrous gas for the nitric acid. 
Though we are ignorant of the exiltence of oxygen in 
the muriatic acid, we at lead know that it may be combin¬ 
ed with that principle by means which we are now going 
to detail. 
The muriatic acid is varioufly employed in the arts ; 
but more elpecially in the art of allaying in the humid 
way. In medicine it is adminillered in a very diluted 
date, as a diuretic and antifeptic ; anddt is the principal 
ingredient in the celebrated remedy of Chabrieres, for 
ruptures. It is externally ufed as an elcharotic ; and 
like wile in gangrenes of the throat, aphthae, &c. Mixed 
with a certain quantity of water, it conltitutes a bath for 
the feet, which is a great fecret with lorae petitioners, 
and is ufed for the purpofe of removing the leat of the 
gout from the nobler to the inferior parts. 
Of OXYGENATED MURIATIC ACID. 
Seheele difcovered that this acid, diftilled with oxyd of 
• manganefe, takes all at once the form of gas; ana that 
this gas was of. a yellow colour, with a Imell analogous 
to '-nitre-muriatic acid, &c. Berthollet, taking up the 
experiments of Seheele, found in this acid many proper¬ 
ties ufeful in the arts. The ancient chemifts called it 
dephtojgtflicated marine acid. 
, Tlie cold method of obtaining it was by pouring mu¬ 
riatic acid over oxyd of manganefe in powder; but this 
procefs was long and expeniive, becaule it was neceilary 
liril to extract the muriatic acid, and much of it was loft. 
The materials ufed for making it atprefent are ioo parts 
of muriat of feda, ©'75 of iulpliuric acid in fifty parts 
of water, and 37^5 of powdered oxyd of manganele. Or, 
two parts of fulphuric acid, three of muriat of loda, and 
one of oxyd of-manganefe. 
Put the muriat of foda and the oxyd of manganefe into 
a large long-necked matrafs, A, placed on a land-bath, 
as exhibited in the Chemiftry Plate IV. fig. 5. The mat- 
rals is flopped with a cork, B, having two holes, or per¬ 
forations ; in one of which is fixed, the tube D, bent down 
to E, ending at the top with a funnel F, by means of 
which the fulphuric acid is poured into the matrafs : the 
other hole in the cork receives the end or a tube, G, 
which bends down till it enters the three-necked bottle 
H, about an eighth part filled with water, into which 
comes alfo the tube of lafety K, to prevent abforption. 
This bottle communicates with the balloon M, by means 
of the tube N, furnifhed like wife with a tube of lafety. 
This fecond veffel is half-full of water, and communicates 
with a two-necked bottle, O, in which is a tube commu¬ 
nicating with the bottle P. Clofe all the joints with fat 
lute, covered with bits of linen dipped in white of egg 
and lime : heat the matrafs by degrees.. As this acid 
dillolves llowiy and with difficulty, a great deal of 
water mult be ufed, coliefted in the different vellels, or 
difpofed in a very high column, fo that, by comprelfing 
the gffs, and giving it a long way to run, it may be com¬ 
pletely dillolved. The fize of the apparatus muft vary 
according to the quantity of oxygenated muriatic acid 
required. Inftead of Woulfe’s bottles, depidted in the 
I S T R Y. 
Plate, calks may be ufed, or (lone receivers, as pradlifeif 
at Jouy, Where a great quantity of this acid is advan* 
tagebufly employed in the bleachiqg of linen. 
Concrete oxygenated muriatic acid. —If the 
bottles be furrounded with ice, the oxygenated muriatic 
acid is obtained cryftalliled at the temperature of © ; it 
is in yellowilh l'pangles ; but it regains its expanliori, and 
would break the velfels, unlefs care be taken to preferve 
the lame temperature, or to leave room for their expan¬ 
fion. In this ftate, the acid lofes its fmell; it is fixed ; 
not being volatile, it cannot have any fmell. In this 
operation,- the fulphuric acid adls immediately upon the 
muriat of foda, to the bafe of which it unites: the mu¬ 
riatic acid, in its turn, attacks the oxyd of manganele; 
one part combines with the oxygen, ami the other to the 
oxyd returning to the metallic ftate; hence refult, ful- 
phat of foda and muriat of manganefe, which remain i:i 
the veffel, and oxygenated muriatic acid which paffes in 
the galeous ftate into the water of the Woulfe’s bottles 
O and P where it diffolves. 
This acid may be obtained in the gafeous fta'te, by 
making it pals through a fmall quantity of water. For 
this purpofe, put the mixture before deferibed into a me¬ 
dicine-phial, or linall matrafs, ftopped with a perforated 
cork ; adapt a bent tube, which is to go under a jar, in 
the.pneumatic apparatus. 
This gas is diftinguilhed by peculiar properties. It 
exhales a ftrong penetrating odour, which affeils the 
throat; it has a ltyptic talte, provokes coughing, and 
draws rheum from the brain ; it will even occalion the 
fpitting of blood ; it dulls the lenfes ; afterwards occafions 
vomiting, probably by fympathy between the pituitary 
membrane or throat and the itomach; it cauies liead- 
ach. The belt remedy for Hopping its effects is liquid 
ammoniac. 
This gas' is net invifible; it is of a greenilh yellow co¬ 
lour. It diminifties and reddens the flame of a taper 
without extinguishing it; but animals cannot breathe in 
it. It is heavier than atmofpherical air : calorie and 
light make no vifible change in it. It burns and flames 
with many combuftible bodies, as metals, lulphur, phof- 
phorus, alkaline and metallic fulphures, volatile oils. 
See. Thus, by throwing iron, antimony, arlenic, or feveral 
metals, in finepovyder theyflameandexhibitalhowerof fire 
very wonderful to thofe who are not acquainted with thefe 
effefls. It does not redden tincture ofturnfule, nor the other 
blue vegetable colours ; but it has the faculty of deltroy- 
ing them, and rendering them colourlefs. If any flowers, 
except yellow ones, be put under a glafs filled with this 
gas,, their colour is quickly deffroyed; green leaves of 
plants undergo the lame change. This effeft can be at¬ 
tributed only to the abforption of the oxygen ; this gas, 
which contains it in excels, gives out a part of it; this 
the flowers abforb greedily, and this abforption deprives 
them of colour : then oxygenated muriatic acid gas be¬ 
comes common muriatic gas again. 
. This gas combines in fmall quantity with water, to 
which it communicates fome of its properties, luch as 
its colour, fmell, and tafte. In this ftate, oxygenated 
muriatic acid is not heavier than common water; which 
lhevvs that it lofes no great quantity of caloric in the 
combination: a proof of it is, that the temperature of 
the water is little altered by combining with this acid. 
This liquid acid has a four aftringent tafte. Expofed to 
the rays of the fun in a tranfparent bottle, oxygen gas 
is clilengaged from it; in proportion as this gas is thrown 
off, the acid lofes its colour and fmell,. and returns to 
the ftate of Ample muriatic acid: this is the pureft oxygen. 
As we laid of the acid gas, this liquid gas does not 
redden blue vegetable colours, but deltroys thifem almoft 
all. This property cauled Berthollet to propole bleach¬ 
ing of thread, linen, and cotton, by its means. Take 
unbleached thread or linen; difeharge the colouring 
principle, by boiling in a ley prepared of twenty parts 
of water with one of potalh, which may be rendered 
more active by means of one-third of lime ; then put 
