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C H E. M 
cular form* This gas is more combuftible than phof- 
phorus with oxygen gas ; phofphorated hydrogen gas 
burns with great rapidity ; infomuch that the experiment 
is even dangerous. Attempts have been made to fubftU 
tute this fluid, inftead of other combuftible matters, for 
the ordinary purpofes of life; to give light and heat, to 
charge fire-arms, &c. Volta has confidered it in this 
lad point of view, and has propofed feveral methods of 
applying it. Neret, in the Journal de Phyfique, has given 
a defcription of a cbafing-diih heated by inflammable air. 
Meflrs. Furftenberger of Bal'd; Brander, mechanic at 
Augfburg; Ehrmann, leflurer in natural philofophy at 
Strafburg; have defcribed lamps which may be lighted 
in the night by the eleftrical fpark. Very pretty artifi¬ 
cial fires are alfo made by means of this gas, with glafs 
tubes, bent in different direhtions, and pierced with a 
great number of finall apertures. The inflammable gas 
is introduced into thefe tubes, from a bladder filled with 
that fluid, and fitted with a copper cock. When the 
bladder is prefled, the '^inflammable air, being made to 
pafs into the tube, ifliies out of all the fmall apertures, 
and is fet on fire by a lighted taper. 
Water abforbs phofphorated hydrogenous gas 3 it is 
then decompofed. It is the air which is in the water 
that.burns it, and the phofphorus flicks againft the fides 
of the veflel. This gas is very injurious to refpiration : 
animals put into it expire immediately. 
Of SULPHUR. 
Sulphur is a combuftible, dry, very brittle, body, of a 
lemon yellow, which has no fmell, unlefs heated, -and 
whofe tafte is very weak, though lufficiently perceptible. 
It becomes eleftric by friftion ; if a piece of a confidera- 
ble fize be expofed to a fudden, though gentle heat, it 
breaks to pieces, with a crackling noife. Sulphur is 
found naturally in great quantities, fometimes pure, and 
fometimes in a Hate of combination. We fhall in this 
place fpeak only of the firft : the following are the varie¬ 
ties of form in which it is found pure. i. Tranfparent 
fulphur, cryftallized in o&ahedrons, whofe two pyra¬ 
mids are truncated : it is depofited by water, moft com¬ 
monly upon .the fiirface of calcareous fpar. Such is that 
of Cadiz. 2. Tranfparent fulphur in irregular pieces ; 
from Switzerland. 3. Whitifli pulverulent fulphur, de¬ 
pofited in iiliceous geodes : flints filled with fulphur are 
found in Franche Comte, &c. 4.. Pulverulent fulphur, 
depofited at the furface of mineral waters ; fuch as thofe 
of Aix la Chapelle, of Enghien near Paris, &c, 5. Cry- 
ftalline fulphur, fublimed ; it is tranfparent, and found 
in the neighbourhood of volcanos. 6. Pulverulent lul • 
phur, fublimed by volcanic fires, without any regular 
form, and often interpofed between loft Hones, as is ob- 
ferved at Solfatara, near Naples. 7* Stalaftites of ful- 
iphur, formed by volcanic fires. 
Befides thefe feven varieties of pure mineral fulphur, 
this combuftible fubftance is found combined with dif¬ 
ferent matters. It is ufually combined with metals, 
which it converts into py'rites, or metallic fulphurs and 
ores. It is fometimes united to calcareous earth, in the 
form of a fulphuric or an earthy liver of fulphur. The 
hepatic calcareous ftones, the fetid fpar, and lwine-ftone, 
appear to be of this nature. Later difeoveries have ad¬ 
ded to the foregoing varieties. Sulphurfeems to be con¬ 
tinually formed in vegetable and animal matters which 
begin to putrefy. Though thefe fpecies of fulphur do not 
appear elfentially, to belong to the mineral kingdom, yet 
we think it proper to join them with the preceding varie¬ 
ties, to render its natural hiftory more complete. 8. 
Cryftallized fulphur, formed by the flow decompofition of 
acuinulated animal matters, fuch as that which has been 
found in the ancient lay-ftall, or dunghill, near the gate of 
St. Antoine. 9. Pulverulent fulphur, formed by the va¬ 
pours difengaged by animal fubftances in a Hate of putre¬ 
faction. It is collected on the walls of ftables, pi ivies, 
&c. to. Sulphur obtained from many vegetables, e(pe= 
l s T R y. 
cially the root of the baftard rhubard (Lapathum), the 
fpirit of cochlearia, &c. This dilcovery, as well as the 
following, was made by Deyeux, member of the college 
of pharmacy, and lecturer in chemiftry. rx. Sulphur, 
obtained in the analyfis of animal matters, particularly 
white of egg, by Deyeux. 12. Sulphur obtained from 
horfe-dung. This combuftible body has been found at 
the inftant of its being emitted. It is probable, that 
lubfequent inquiries will difeover this body in a great 
number of animal fubftances. 
None of thefe fulphurs are ufed in the arts. The ful¬ 
phur of commerce is extracted, by diftillation, from me¬ 
tallic fubftances, called pyrites. In Saxony, and in Bo¬ 
hemia, this mineral is put into earthern tubes, placed on 
a long furnace ; the ends of the tubes, which ifl'ue out of 
the furnace, are received in fquare iron veflels, contain¬ 
ing water; the fulphur is collected in thefe receivers, but 
is very impure. In order to purify it, it is melted in an 
iron ladle; the earthy and metallic parts fubfide to the 
bottom. It is then poured into a copper boiler, where it 
makes another depofit of the foreign matters' which con • 
taminated it. After having been kept a certain time in. 
fufion, it is poured into cylindrical wooden moulds, 
which give it the form it ufually has in commerce ,- that 
which is precipitated to the bottom of the boiler during 
the fufion, is grey, and impure: it is very improperly 
called fulphur vivum. In other countries, as at Ram- 
melfberg, the fulphur is extracted from pyrites, in a 
more fimple manner. The fulphur, which is found 
melted among the mafles of pyrites, roafted in the open 
air, is taken away with ladles, and purified by a fubfe- 
quent fufion. 
Sulphurated matchesare commonly notliingbut threads 
of cotton dipped in melted fulphur; the fame thing is 
done with little bits of wood, then called matches, and 
likewife pieces of ftraw. 
_ Aclion of Caloric upon Sulphur. —Put fulphur into a cru¬ 
cible; place it upon burning coals, it foon enters into 
fufion. This firft fufion is liquid; but, keeping the ful¬ 
phur a few moments longer on the fire, it acquires a 
much firmer confidence. While in this ftate, pour it 
into an earthern pan full of water; it will be found to 
have acquired a red colour, and to be as loft as wax ; it 
yields to the touch, inftead of being dry and brittle like 
common fulphur. In this ftate, it is fuccefsfully ufed 
for taking impreflions of feals or engraved ftones. Sul¬ 
phur may alfo be eafiiy reduced to gas and volatililed ; 
but this gas is not permanent, it becomes folid in a cool¬ 
er temperature: this property ferves to its purification. 
Common fulphur in powder is put into a cucurbit of 
glafs, or glafed earth, to which aludels are adapted, 
which mutually cover each other. Thefe are all perforated 
at the bottoms, except the laft, which is terminated by 
an inverted funnel. Place the cucurbit in a fand-bath, 
and put on the head ; lute the joinings with (trips of pa¬ 
per dipped in (larch ; add a receiver to the neck of the 
veflel merely to prevent communication with the exter¬ 
nal air; then proceed to fublimation with a moderate 
heat. As foon as the fulphur begins to melt, it fublimes 
rifing in a white thick fmoke, which is condenfed, and 
adheres to the infideof the head in form of a powder. 
When a fufticient quantity is obtained, let the fire out, 
leave the veflels to cool, unlute the head, and colleft the 
fublimed produft with a feather : this is called fulphur 
in flowers, or flowers of fulphur. Then proceed to a frefli 
fublimation, and fo continue till you have fublimed all 
the fulphur. Sublimed fulphur contains oftentimes a 
little fulphuric acid, formed by the combuftion of a 
finall portion of the fulphur by means of air contained 
in the veflels. It is thoroughly purified by walhing. 
Sulphur ought to be prepared in this way for all medi¬ 
cal, and the nicer chemical, purpofes. 
If, inftead of taking the fulphur in a ftate of thicknefs 
or congelation, it be drawn from the fire immediately af¬ 
ter it is melted, and left to cool (lowly, its parts take a 
(ymmetj'ical 
