CHEMISTRY. 
292 
tion. Sulphuric acid diluted with a fmall quantity of 
water, adts likewife on tin ; but the folution is more per¬ 
manent, and affords a lefs abundant precipitate, on the ad¬ 
dition of more water. In this combination the tin feizes 
the oxygen of the fulphuric acid, in fitch quantities that 
fulphur is very fuddenly formed. This lubftance gives 
the folution a brown colour while it is warm, and is pre¬ 
cipitated as foon as it becomes cold. When the folution 
is more ftrongly heated, the tin is precipitated in the 
form of a white oxyd. The fame phenomenon takes 
place without the afliftance of heat, though in a much 
longer time. Tin dilfolved in the fulphuric acid is very 
cauftic. Monnet, by cooling, obtained cryftals fimilar 
to calcareous fulphat, or fine needles, intermixed with 
each other. The oxyd of tin precipitated from its folu¬ 
tion by handing, or by heat, is foluble in the fulphuric 
acid. If the fulphuric folution of tin be evaporated to 
• drynefs, the oxyd it affords is of a grey colour, very 
difficult of redufiion, and no longer foluble in the acid. 
Alkalis precipitate tin from the fulphuric acid, in the 
form of a very white oxyd. 
Nitric acid is decompofed by tin, even in the cold, 
with a fingular degree of rapidity. This folution is one 
of the molt ftriking and rapid among chemical pheno¬ 
mena. It appears that tin has a very itrong tendency to 
unite'with the oxygen of the nitric acid; and as azot is 
far from adhering as ftrongly to the oxygen in this acid, 
as fulphur to the fame principle in the fulphuric acid, it 
is not furprifmg that the decompofition of the former by 
tin fhould be much quicker than that of the latter by 
the fame metal. Morveau has obferved, that, in a folu¬ 
tion of tin by the nitric acid, no gas is dilengaged, but 
that ammoniac is formed. We fee, therefore, that the 
tin not only decompofes the nitric acid, but likewife the 
water, fince it can only be the hydrogen of the water, 
which, uniting to the azot of the nitric acid, forms the 
ammoniac produced in this operation. The tin is con¬ 
verted into a white oxyd, which Macquer in vain at¬ 
tempted to reduce. The metal in this ftate appears to 
be fuperfaturated with oxygen. The nitric acid holds 
but a very fmall quantity of the metal in folution ; and 
when evaporated with the intention of obtaining cryf¬ 
tals, the dilfolved portion quickly precipitates, and the 
acid remains nearly in a ftate of purity. Bucquet how¬ 
ever affirms, that a nitratof tin, whofe form he has not 
determined, may be obtained from this folution ; it is 
very deliquefeent. He likewife afferts, that if the oxyd 
of tin, produced by the decompofition of the nitric acid, 
be wafhed with water, the fluid diffolves a fmall quantity 
of the nitrat of tin, which may be obtained by evapo¬ 
ration. The nitric acid retains a fomewhat larger quan¬ 
tity of tin in folution, when it is ufed in a very diluted 
ftate ; but it let its fall by ftanding, or by the applica¬ 
tion of heat. Bayen and Charlard, in their valuable 
inquiries concerning tin, have difeovered, that when the 
nitric acid is charged with all the tin it can oxydate, fo 
as to become thick and incapable of adfing on new por¬ 
tions of the metal, a ftanno-nitrous fait is obtained, by 
waffling the mafs with a large quantity of diftilled water, 
and evaporating the water to drynefs, which fait detonates 
alone .in a heated veflel, and burns with a white and 
denle flame, like that of phofphorus. This fait is not a 
nitrat of tin, but a kind of triple fait or nitrat of am¬ 
moniac and tin. Diftilled in a retort, it fwells up, boils, 
and inftantly fills the receiver with a white thick vapour 
of a nitrous fmell. 
The fuming muriatic acid adts ftrongly on tin, and 
diffolves it by the help of a gentle heat, and even in the 
cold, inftantly lofing its colour and property of emitting 
fumes. The very flight effervefcence which takes place 
in this combination difengages a fetid inflammable gas 
from the mixture, not at all refembling the fmell of ar- 
fenic, as fbme chemifts have affirmed. The water is there¬ 
fore decompofed by the tin with the afliftanceof the acftL 
The muriatic acid diffolves more than half its weight of 
tin ; the folution is yellowifn, of a very fetid fmell, and 
does not afford a precipitateof oxyd of the tin like two laft 
mentioned acids. By evaporation it affords brilliant and 
very regularly formed needles, which attraft the humidity 
of the air. If this fait be diftilled in a retort, with a re¬ 
ceiver adapted, the water of cryftallization will firft ap¬ 
pear, then fome fuper-oxygenattd muriat of tin will be 
volatiiized, and an oxyd of tin remains in the retort. If 
to a recent folution of muriat of tin, be added a folution 
of gold, a purple precipitate is formed, known by the 
name of precipitate of CaJJius ; but the precipitation will 
not take place if the oxygenated muriat of tin be ufed 
inftead of the common muriat. 
Oxygenated muriatic aciddiffolves tin very readily, and 
without fenfible effervefcence, becaufe that metal quickly 
abforbs the fuperabundant oxygen from the acid, and does 
not require any decompofition of the water to effedf its 
oxydation. The folution has then all the charadfers of 
the preceding. If a muriatic folution of tin be left in 
contaft with air, it becomes oxygenated; the fame effedt 
takes place with the red oxyd of mercury, and the oxy¬ 
genated muriat of mercury. 
Nitro-muriatic acid, made with two parts of nitric 
acid and one of muriatic acid, diffolves tin with effer¬ 
vefcence. A ftrongheat is excited, which mult be check¬ 
ed by plunging the mixture into cold water. To form a 
permanent folution of tin in this mixed acid, the metal 
mull be added by fmall portions at a time, one portion 
being buffered entirely to difappear before a fucceeding 
one be added; if the whole were addpd at once, great 
part of the metal would be oxydated. Aqua regia, by 
this management, will diffolve half its weight of tin. 
The folution is of a reddifh brown, nearly tranfparent, 
and frequently, in a few feconds, becomes converted 
into a tremulous jelly, of the appearance of rofin. Some¬ 
times it becomes concrete, on the addition of half its 
weight of water, though it was perfectly fluid before: 
but the jelly formed by the addition of water is of an 
opal colour, becaufe, according to the remark of Mac¬ 
quer, the folution itfelf being decompofable by water, a 
portion of the oxyd of tin is precipitated, ami deftroys 
the tranfparency of the jelly. 
Tin decompofes the corrofive mercurial muriat. To 
effedt this, the tin is firft divided by the addition of a 
fmall portion of mercury ; equal parts of this amalgam, 
and the corrofive mercurial muriat, are triturated toge¬ 
ther, and the mixture expofed fo diftiilation in a glafs 
retort, by a very gentle heat. A colourlefs liquor firft 
paffes over, and is followed by a thick white vapour, 
which ifiues with a kind of explofion, and covers the in¬ 
ternal furface of the receiver with a very thin cruft. The 
vapour becomes condenfed into a tranfparent liquor, 
which continually emits a thick, white, and very abun¬ 
dant, fume. It is called the fuming liquor of Libavius, 
and is the combination of the muriatic acid and tin, the 
acid appearing to be fuperfaturated with oxygen. Adet, 
who read a memoir to the Academy upon the fuming li¬ 
quor of Libavius, has fliown, 1. That the effervefcence, 
which takes place as often as it is mixed with water, de¬ 
pends on the difengagement of an elaftic fluid, which 
polleffes all the properties of azotic gas. 2. That the 
fuming liquor, combined with water, in the proportion 
of feven to twenty-two, forms a folid body, which melts 
by the adtion of heat, congeals by cold, and refembles 
the oxygenated muriat of tin, or butter of tin. 3. That 
the fumingliquor, diluted with water, diifolves tin with¬ 
out the difengagement of hydrogen gas, and affords a 
fait fimilar to that which is obtained by thediredt combi¬ 
nation.of the muriatic acid and tin. He concludes, from 
his various experiments, that the fuming liquor is no¬ 
thing elfe but a compound of the muriatic acid in the 
aeriform ftate, and the oxyd of tin in which oxygen pre¬ 
dominates ; and that this fait is the fame, with reipedt to 
the common muriat of tin, as the oxygenated muriat of 
mercury is to the muriat of mercury, or mercurius dulcis . 
The 
