t‘>!'ustris. 
t‘cca. 
^^phtha 
INFLAMMABLES. 74. Bitumen. 229 
Of a dark co’our, confolidating in the air, binning quicker 
and with iefs ofFenfne fnrnts 
Humus vegetiihilii. ^yft. nai. xd. 3. p- 2!0. «. 6, 
Humus combull'.bilis. PP'alL ! />■ 2I- «• 7 ’ 
Peat. Kirvjan minerul. 2 . p 6z. 
Found every where in bogs and morafies, and is generally rho 
middle and lower beds under turf, and frequently at the 
bottom of bogs where the water has lain llagnant : the vege- 
table fubftances arc in quite a decayed Hate, and therefore lefs 
viiible : a brick of 14 inches long, 6 broad, and ^ ihicl, r.'ill 
weigh from a pound and a quarter to a pound and three 
quarters: it is, in many places, a prir.cip.l artioe of fuel, 
and its alhes arctrf confjde-rable value as a manure. 
Of a dark colour, coiifolidating in the air, a little greafy 
to the touch, impreguated with a large proportion of 
bitumen, and burning wiih much heat and fumes. 
Turfa folida, Cronft. win- 284. z, i. i. * 
Found on plains at the top-s of higher mountains, frequently on 
thofe compofed of gramie, anti at the bottom oi ilignant wa- 
ters: after being fometime kept it will burn like coal: ;t 
the moil; ponderous ot its kind, a brick 14 ineiics lo.ng, 6. 
broad, and 4 thick, weighing about two pounds. 
74. BITUMEN. Eafily combuftlble with flair.e^ 
and emitting when ignited a Ifrong odour, gr^a- 
ly to the tout h. 
. Fluid, whitifli, volatile, highly inflammable. 
Bitumen fiuidunr. Syji xii. 3* toq, w. i. 
Bitumen fluidiflimum. ff oh fy^t. 2. p. 89. «. >■ 
Oleum montanum. IVolder/u. min. 24. 
Naphtha. Kir'V<an mineral. 2 - 42. 
• Naphtha. Schmeifser miner, l. p. z 9 ,^. 
Naphtha. ’Thomfon chem. s^. p 8. 
Found principally in Perfta and Media, where it oozes like 
water out of fand-ftoneq is fluid and tranfparent, fwims on 
alcohol and is infotublc in it, catches Are on the approach of 
flame, burns with a white flame and leaves hardly any reft,- 
duum’ : it is fo volatile, that in warm weather it fills tho 
atmofphere around it with its odour : has fomewhat of a (harp 
talk, and is not mifcible with water: after expofure to the 
air, it becomes yellow, and afterwards brown ; its confilknee 
is increafed, and at laft it paflies into petroleum : fpecifis, 
gravity when white 729, when yellow 847. 
