3^8 C H E M 1 
formed by the combination of the tartareous acid and 
iron. The one is foluble martial tartar, confiding of one 
pound of the tartarized tindfure of Priars, and four 
ounces of-tartarit of potafh, evaporated to drynefs. The 
other is known by the name of martial balls. They are 
made by mixing, in a glafs veffei, one part of fteel filings, 
and two parts of white tartar in powder, with a certain 
quantity of brandy -; when the brandy is evaporated, the 
mafs is pulverized, and more brandy added, which is 
buffered to evaporate as before. This procefs is re¬ 
peated till the mafs becomes tenaceous, when it is formed 
into balls. 
Pott and Margraaf treated tartareous acidule with the 
mineral acids, and the latter obtained neutral falts, fimi- 
lar to thole afforded by each of thefe acids with potafli; 
whence he concluded, that this alkali exifts, ready form¬ 
ed, in this acidule. Rouelle the younger made a num¬ 
ber of accurate experiments, which afforded the fame 
refults. A pound of tartareous acidule, in very fine 
powder, was added to a pound of concentrated fulphn- 
ric acid: the mixture became hot, and the mutual ac¬ 
tion of the two fubftances on each other was affifled by 
the heat of a water-bath, and by frequent ftirring with a 
glafs inftrument. This heat being continued ten or 
twelve hours, the mixture became of the thicknefs of 
cream, at which time two or three ounces of boiling di- 
ftilled water were added, which rendered the whole fluid. 
Two hours after, the mixture was taken from the fire, 
and three pints of boiling diftilled water were added. 
This folution was coloured, and opake, and contained 
difengaged fulpliuric acid, a portion of tartareous aci¬ 
dule not decompofed, and fulphat of potafli. The excels 
of fulpliuric acid was then faturated with chalk ; and 
fulphat of lime, with a fmall quantity of tartareous aci¬ 
dule, was precipitated. The mixture was then filtered 
and evaporated, till it became reduced to eighteen or 
twenty ounces; during which, a fmall quantity of tar¬ 
tareous acidule and of fulphat of lime fell down. The 
fluid was decanted off, evaporated a fecond time, and, 
by Handing, afforded cryftals of fulphat of potafli; more 
of which was obtained in the like manner by fucceflive 
operations. This fait is always mixed with a fmall 
quantity of tartareous acidule, and burns on a hot iron. 
But, if a due quantity of diftilled water be added, it will 
be taken up, and the tartareous acidule will remain un- 
diflfolved. The foregoing procefs is defcribed by Ber- 
niard, who repeated it with fuccefs after Rouelle. The 
nitric and muriatic acids, treated in the fame manner 
with tartareous acidule, afford nitratand muriat of pot¬ 
afh ; which incontrovertibly proves the exiftence of pot¬ 
afh in this fubftance. 
Tartareous acidule acquires folubility, by uniting 
with borax and boracic acid, affording a preparation 
called foluble cream of tartar. Various receipts are in 
exiftence for making this ; we (hall give two, which feem 
to anl'wer the purpofe belt. 
i. Tancoigne, of Paris, formerly prepared his foluble 
cream of tartar with one part of cream of tartar, and the 
fifth part of its weight of borax in powder ; but this pro¬ 
cefs gave a cream of tartar which attradled the moilture 
of the air. To avoid that inconvenience, he fubftituted, 
with advantage, the boracic acid ; but, inftead of one- 
fifth of borax, he employed half the weight of acid. Dif- 
folve the whole in a glazed pot, with about three times 
its weight of water; filtre the liquor cold, and then eva¬ 
porate to drynefs. As the evaporation goes forward, the 
fait takes a glutinous tenaceous confiftence. When the 
matter is dry and brittle, pulverize it, and (hut it clofe 
in a vuTel. 
z. Procefs of Lartigue, ofBourdeaux. Take one part 
of cryftallized boracic acid in powder; put it in twice 
its weight of pure water over a gentle fire, in a velfel 
which will not be injured by vegetable acids. When 
hot, put in by degrees, and ftirring it continually, eight 
parts of tartareous acidule in fine powder ; this will form 
S T U Y. 
a very ftiff pafte. Keep the pGt on the fire, and ftir it till 
it becomes dry, breaking the clots, and taking care'that 
the matter does not burn to the fides and bottom of the 
vefiel. Then reduce it to powder, and flit it through a 
fine fieve. 
The combinations of the tartareous acidule with earths, 
have not been yet fufficientiy examined. Lime decom- 
pofes it; and it unites very well with the different alka¬ 
lis. If it be added to a folution of carbonat of potafli, a 
ftrong effervefcence is immediately produced, by the dif- 
engagement of the carbonic acid. The acidule tnuft be 
added to faturation, and the liquor filtered, after having 
boiled for half an hour; after which, the evaporation 
being continued till a pellicle is formed, the folution, by 
flowly cooling, affords long quadrangular prifms, ter¬ 
minated by two facets, placed flantwifer This fait is 
known by the names of vegetable fait, foluble tartar, tar¬ 
tarized tartar, and ought to be called tartarit of potafh. 
It has a bitter tafte ; is converted into a coal by a ftrong 
heat ; and is decompofed by diftillation, affording an 
acid phlegm, oil, a large quantity of carbonic acid, and 
a fmall quantity of ammoniacal carbonat. Itflightly at- 
tradfs the humidity of the air, and is completely difloived 
in four parts of water, at the heat of uo degrees of 
Fahrenheit. This folution is decompofed during the 
courfe of fome months, and leaves the fixed alkali com¬ 
bined witii the carbonic acid. The mineral acids de- 
compofe it, and precipitate tartareous acidule ; it is alfo 
decompofed by raoft metallic folutions. Lime-water de- 
compofes it, forming an infoluble tartarit of lime. 
Tartareous acidule, combined with foda, forms fait of 
Seignette, fo called from the name of an apothecary of 
Rochelle, whofirft compofed it. Vauquelin had lately dis¬ 
covered that this is a triple fait, and we now give it the 
name of tartarit of potafb and foda. It is prepared by 
dilfolving twenty ounces of acidule of tartar in four 
pounds of water, and gradually adding very pure cry- 
ftallized carbonat of foda to faturation, which point is 
known by an effervefcence not being excited by the ad¬ 
dition of more alkali. In this combination the tartare¬ 
ous acidule is rendered loluble. The fluid being evapo¬ 
rated till it has nearly the confiftence of fyrup, affords, 
by cooling, very beautiful regular cryftals, often of a 
confiderable magnitude. They are prifms of fix, eight, 
or ten, unequal faces, truncated at right angles at their 
extremities. Thefe prifms are moft commonly bifected 
length wife: and the large face, or bafe, on which they 
reft, is marked by two diagonal lines, interfering each 
other, and dividing the bafe into four triangles. 
To he affured that this was a triple fait, Vauquelia 
made the following experiments, i. He evaporated the 
combination of pure tartareous acid and foda ; and he 
obtained a faltmuch lei's foluble than the fait of Seignette, 
which cryftallizes in very fmall needles, or in thin irre- 
gular plates, and never like tartarit of foda. z. Hemixed 
together a very concentrated folution of neutral tartarit 
of loda, and of vegetable fait equally concentrated, which 
did not cryftallize feparately; but, as foon as the li¬ 
quors were mixed, he obtained eight-fided prifms exarily 
fimilar to the fait of Seignette. Here then is an acidule 
formed by tiie addition of tartareous acid. From the 
enquiries of Vauqueiin it appears, that ioo parts of the 
cream of tartar of commerce contain feven parts of tar~ 
tarit of lime, and that ioo parts of crude tartar contain 
about o'i6. And it appears, that the fame refults as 
above would be produced with the neutral tartarits of 
lime, antimony, and iron. 
This fait has a buter tafte; is decompofed by the fire, 
like the tartarit of potafli; efflorefces in the air, becaufe 
it contains much water of cryitailization, and is nearly 
as foluble as tartarit of potafli, and, like that fait, is de- 
compoled by air, mineral acids, and metallic folutions. 
The mother water of this lalt contains the portion of 
tartarit of potafli, which compofes part of the tartareous 
acidule. 
Ammoniac 
