pwn en OA SPURT LA te hee oy 
44 Mr Harener t's Obfervations on Bituminous Subjlances. 
“The charaéters of bitumen are much more apparent in turf and 
peat, than in'the greater part of the foffil woods. Turf is well known 
to be compofed of the parts of vegetables, fuch as fmall roots, 
twigs, &c. mixed with a portion of petroleum; and peat is the 
fame, excepting that it generally contains more of earthy matter, or 
that the vegetables have undergone a more complete secott 
pofition. | 
The boggy nature'of the places in which they are found, proves 
that a certain degree of maceration is neceflary to form the bitu- 
minous matter which they contain; and Ihave already noticed, 
that every fa&t appears to demonftrate, that the bitumen is a pro- 
duct of thofe vegetables, the remains of which conftitute aw other 
ingredient of turf and’ peat. 
The different proportion of vegetable matter, of bitumen, ‘and of 
earth, together with the different ftate of the bitumen, as well as 
the degree of perfection refpeéting the formation of it from the 
vegetable principles, contribute to alter the properties and characters 
of the compound, and thus produceivarieties.. It is believed that 
thefe fubftances have been materially concerned in the formation of 
pit-coal, and fome eminent mineralogifts maintain that there is an 
uninterrupted feries which conneéts the varieties of turf and peat 
with thofe of coal*. 
| § 6. 
vented, but alfo of all putrid vegetable and animal bodies es it is found in vegetable 
and animal manures that have undergone putrefaction, and is the true bafis of their ame- 
liorating powers 5 if the water that paffes through a putrefying dunghill be examined, it 
will be found of a brown colour, and if fubjeéted to evaporation, the principal part of the 
refiduum will be found to confift of coal. All foils fteeped in water communicate the 
fame colour to it in proportion to their fertility ; and this water being evaporated, leaves 
alfo a coal, as Meffrs. Haffenfraz and Fourcroy atteft.”—Kirwan on Manures, B 1545 
Vol. v. of The Tranfaétions of the Royal Irifh Academy, 
* Man findet in der natur einen ununterbrochenon tibergang von dem rafen und 
papiertorf 
