CHEMISTRY. 
different fpecies of inflammable gas, formerly called fuj- 
phurated, pholphorated, carbonated, arfeniated, oleagin¬ 
ous, Sec. hydrogen gas. It decompofes feveral metallic 
oxyds, and acids with Ample and known radicals; im¬ 
parts to all the compounds into which it enters, whether 
they be .combuftible or not, a contiderable refringent 
power, which property led Newtoii to conjecture, that a 
combuftible fubltance wa$ contained in water ; becomes 
Axed in organized bodies, and forms one of the princi¬ 
ples of the mixed combuitibles they contain. 
Sulphur, is a yellowilh lubllance, odorate, eledhic, 
tranlparent and odftaedral, op a Ice and prifmatic, and fu- 
fible. It is fulceptible of two kinds of combultion ; the 
one flow, with a bine flame, and the' formation of ful- 
phurous acid ; the other rapid, with a white flame, dur¬ 
ing which fulphuric acid is produced. It combines with 
earths and alkalis; becomes ioluble when thus combined,- 1 
unites with metals, and forms l'ulphurous ores ; and exilts 
in the earth in very large quantity, either alone, or com¬ 
bined with metal. 
Phosphorus is a white, tranfparent, chryftallized, 
lamellated, and extremely fuiible, fubltance. It burns 
in two modes ; (lowly, in every temperature with which 
we are acquainted, emitting a white flame and acrid 
odour, and formingphofphorous acid ; rapidly, inatem- 
perature of 147 0 , with a vivid and very brilliant flame, 
without any perceptible odour, and forming phol'phoric 
acid. It is never to be found pure in a native ftate, on 
account of its extreme combuftibility; unites with lul- 
phur, and with metals; is Ioluble in hydrogen gas; takes 
away oxygen from feveral metals, and Separates them 
from acids, relloring their proper form and metallic 
luftre ; and exifts more abundantly in. the mineral king¬ 
dom than in the animal, to which it was once exclufive- 
ly attributed. 
Carbon is the combuftible matter of coals, fuppofed 
pure and ifolated from earths, alkalis, falts, &c. It is 
combuftible in a great degree of heat; forms carbonic 
acid when united with oxygen; has the ftrongelt attrac¬ 
tion for oxygen of any known fubltance, and deprives 
all other burnt bodies of this principle; exilts in abun¬ 
dance in animals aiftl vegetables, conftituting almoft 
wholly the folid bafis of the latter, and on that account 
remaining, and preferving their form, after tippy are de¬ 
composed, cither l'pontaneoully, or by theadtion of ca¬ 
loric ; is foluble in alkalis, and hydfogen gas; unites 
with metals, forming with iron, in particular, iteel, and 
carbure of iron, improperly called plumbago, lead ore, or 
black lead ; and is found in each of the natural kingdoms. 
Metals are well known for their great ponderoftty 
and luftre : they are fufible, cryftallizable, and combuf¬ 
tible ; decompofe water and leveral acids ; unite with 
Sulphur, phofphorus, carbon, and each other, at different 
temperatures ; and in their Hate of oxyds, perform a dou¬ 
ble funftion. that of acids with earths and alkalis, and 
that of falifiable bales with acids. This genus differs 
from all that precede, particularly in the number of its 
fpecies. To give a juft idea of thefe, of which there are 
feventeen with which we are weil acquainted, and this 
number will probably be Iriil farther increafed by new- re- 
learches, we fhall divide this genus into five le&ions: the 
firft comprifes brittle and acidinabie metals; of which 
there are three, arfenic, tungften, and molybdaena. The 
fecond includes thofe which are brittle, and limply ca¬ 
pable of oxydation, of which we reckon live fpecies; co¬ 
balt, bifmuth, nickle, manganeSe, and antimony. The 
third leftion contains the femi-dudtile and oxvdable me¬ 
tals, of which there are two; zinc and mercury. The 
fourth Sedtion comprehends Inch metals as are perfectly 
dudfile, and eafily oxydable, which are tin, lead, iron, 
and copper : and the fifth, includes all thole that are per¬ 
fectly duCfile, but oxydable with difficulty, which are 
filver, gold, and platina. As a diftinCt head is referved 
for the moil important chemical properties of metals, it 
will be fufficient here to exhibit briefly fome 1'peciiic dif¬ 
r 59 
ference of each of thefe bodies ; obferving, that the ap¬ 
pellations of fetni metals, imperfedl metals, tn\A perfedl me¬ 
tals, manifestly originating from the erroneous ideas of 
alchemy, ought to be difcarded from the language of a 
fcience that has any pretention to accuracy. 
1. Arfenic is lamellated, of a bluifh grey colour, bril¬ 
liant and fragile; and burns with a blue frame, and a 
fmell refembling that of garlic. 2. Tungften-is of a grey 
white colour, ■ granulated, friable, almolt infufible, and 
fcarcely foluble in acids, though extremely oxydable and 
acidifiable by the operation of air and caloric. 3. Molyb- 
dsena is in the ftate of powder, or grains, blackifh, Shin- 
ing, agglutinated, fragile, very little fuiible, and by burn¬ 
ing becomes a white, volatile, prifmatic, and acidifiable 
oxyd. 4. Cobalt is granulous, fine, of a roly white co¬ 
lour, fragile, pulverable, difficult of fufion, and becomes 
blue when melted with glafs. 5. Bifmuth is in large la¬ 
minae, of a yellowilh white, brittle, eafily fufible, very 
cryftallizable, and extremely oxydable. 6. Nickel is grey, 
granulous, hard, a little fragile, extremely difficult to 
lul'e, and affords a green oxyd by means of caloric and 
air. 7. Manganeie is of a grey white colour, and fine 
grain, brittle, very difficult to fufe, and of all metals 
the molt combuftible in the air alone, fo that it changes 
colour immediately on expofure to it, and is reduced to 
a black dull in the courfe of a few days. It Ihould be 
kept underneath alcohol, or oil, to prevent it from burn¬ 
ing. 8. Antimony is of a pure white, in large laminae, 
brittle, hard, to fufe, and Sublimes on combultion in the 
air into a white, cryftailized oxyd, which almoft adts the 
part of an acid in uniting with alka.lis. 9. Zink is of a 
blue -white colour, in large laminae, femi-fragile, in fome 
degree malleable, eafy to fufe, the moft inflammable of 
metals, burning, when red hot, with a beautiful yellow¬ 
ilh white flame, and powerfully decompoiing water, ra. 
Mercury is fufible at 30° below o of Reaumur’s thermo¬ 
meter, and congeals at 31°; becomes a black oxyd. 
(cethiops per fe) by mere divifion, or is extinguished by 
this Simple procefs in every vifeous or confident matter 
with which it is triturated, n. Tin is of a brilliant 
white colour, foft, light, little, Sonorous, capable of be¬ 
ing Scratched by the nail, ver\ fuiible, very'combuftible, 
and affords a white oxyd, which deftroys the transparency 
ot glafs, and converts it into enamel. 12. Lead is of a 
dull bluifh colour, heavy, foft, extremely fufible, and af¬ 
fords an oxyd the moft vitrifiable of all we know, and a 
laf's of a yellow hue, refembling that, of a topaz. 13. 
ron is white, fibrous, the nioft tenacious of metals, very 
difficult to fufe, very combuftible, and the metal moft 
attradied by the magnet. It readily decompofes water, 
changes to a powder in the air,unites with a carbon, which 
converts it into fteel, and is the only metal any way abun¬ 
dant in the two organic kingdoms. 1 4. Copper is of a 
fine Shining red, very foft and dudtile, odorate, and poi- 
fonous. It bums with a green flame, and affords brown, 
blue, and green, oxyds, the laft of which is formed in 
damp air. 1 5. Silver is of a pure and brilliant white, des¬ 
titute of fmell and tafte, very dudtile, not oxydable by 
caloric and air, burning with a greenifh flame by the elec¬ 
tric Ihqck, growing black from the fumes of Sulphur, un¬ 
alterable by the air alone. 16. Gold is of a fine brilliant yel¬ 
low, extremely dudtile, lefs combuftible and leis oxydable 
than Silver, and even lei 11 lefs alterable than it by the 
contadt of air. It is convertable into a fine purple oxyd 
by the cledtric (hock. 17. Platina is the lieavieft, molt 
infufible, leaft combuftible, and leaf! alterable of all me¬ 
tals. It is of a grey white colour, poffeffes little brilli¬ 
ancy, and may at Some future period become one of the 
molt valuable inlfruments of the arts. 
Compound combuftible bodies are all fuch as refult 
from a combination of feme of the preceding ones : thus 
the Solutions of Sulphur, carbon, phofphorus, and arlenic, 
in hydrogen gas, are compound inflammable gales : and 
the combinations of Sulphur with phofphorus, of carbon, 
with iron, of different metals with Sulphur, phofphorus. 
