P I N U S. 
Mr. Meu'/.ies, who brought a few fmall plants from 
London; fome of which were (landing in the year 1807, 
and the largeft then meafured thirteen-feet in circum¬ 
ference. His grace has been in the conftant habit, for 
more than thirty years., of ufing larch of various ages for 
different purpofes; and he pofitively affirms that the 
thinnings of his plantations, employed for paling, rails, 
and hurdles, “are more durable than oak copfe-wood of 
twenty-four years’ growth.” He builds all his ferry-boats 
and fifhing-veffels of larch 5 and, after a lapfe of years, 
they have proved found, when the ribs, which were made 
of oak, have become decayed. In mill-axles, alfo, larch 
has been fubftituted for oak with the bell efteCt; and, 
in cutting up an old decayed mill-wheel, thofe parts of 
the water-cogs which had been repaired with it twenty 
years before were difcovered to be as found and as frefh 
as at firff. The value of larch is not to be eftimated 
merely by its intrinfic qualities, but alfo by its aptitude 
to foils and fituations where few other trees can live. 
On the very fummit of the lower range of the Grampian 
hills, from a thoufand to twelve hundred feet above the 
level of the fea, on a barren foil compofed of mountain- 
fchift, Hate, and iron-done, and where even the Scotch fir 
cannot rear its head, the lareh grows luxuriantly ; “and 
in conliderable traCls,” fays the duke, “ where fragments 
of (hivered rocks are firewed fo thick that vegetation 
fcarcely meets the eye, the larch puts out as ftrong and 
vigorous (hoots as are to be found in the valleys below, 
and in the mod: fheltered fituations.” The larch is an 
alpine tree, and it will not thrive in wet fituations : but 
its comparative value is exceedingly greater than the 
Scotch fir when it finds a congenial foil. The duke fold 
a larch that was fifty years old for twelve guineas, while a 
fir of the fame age and in the fame fituation was not 
worth more than fifteen (hillings. 
In addition to the other valuable properties of this 
tree, Mr. White has communicated to the Society of Arts, 
the refult of fome experiments decifive of the ufe of bark in 
tanning. While fome of his workmen were taking off the 
bark from a number of larch-trees intended for building, 
they found the nails of their fingers ftained, which induced 
him to try whether it would tan leather or not. He procu¬ 
red two calf-(kins,of equal price, weight,and fubftance,and 
immerfed one in an infufion of oak-bark, of very fine 
quality, and the other in the fame proportion of larch- 
bark, from a very ftnall tree, each (kin remaining exa&ly 
the fame time in its refpe&ive tan-pit; and, during the 
operation, he repeatedly weighed a meafure of larch- 
liquor againft the oak, and always found the former to 
preponderate ; the confequence was, that the (kin tanned 
with larch felt thicker in the hand, and heavier, and was 
finer in the grain, and of a lighter colour, than that tanned 
with oak. For this communication, Mr. White waspre- 
fer.ted by the Society of Arts with a gold medal in the 
year 1813. See their Tranf. vol. xxxi. for that year. It 
is proper alfo to obferve that Mr. White’s father had 
received nine gold and two filver medals (from the 
fame Society) for planting thofe trees which the fon is 
now converting to fo valuable a purpofe. 
L he refinous juice of the larch is the turpentine of 
commerce. It ifiues fpontaneoufiy from the bark ; but is 
more commonly obtained by boring a hole with an auger 
about two feet above the ground, till it reaches near to 
the heart of the tree ; into this hole is inferted a fmall 
pipe or cock, through which the turpentine flows into 
proper veffels placed for its reception. This procefs 
is continued from the end of May to the end of Sep¬ 
tember. When.the.trees will yield no more for that fea- 
fon, the turpentine is preffed through a cloth to purify it. 
This is ulually thinner than any of the other forts, of a 
clear whitifh or pale yellowilli colour, a hot pungent bit- 
terifli difagreeable tafte, and a ftrong fmell, without any 
thing of the aromatic flavourof the Chian or Cyprus tur¬ 
pentine obtained from the Piftacia terebinthus. The com¬ 
mon and Straftmrgh turpentine is from the Pinus picea : 
479 
and the Canada balfam, which may be confidered as the 
purefl of the turpentines, is procured from the filver and 
balm-of-Gi!ead firs. 
The turpentine is not to be obtained in confiderable 
quantities from very young trees, and in old ones it gra¬ 
dually dries up, till at laft it affords none : it is only af¬ 
ter the tree has attained the thicknefs of ten or twelve 
inches in diameter, that it is thought worth while to col- 
left the turpentine; and from that time, during forty or 
fifty years, if it continues fo long in vigorous growth, the 
tree will continue to yield annually from feven to eight 
pounds of turpentine. 
All the turpentines diffolve totally in rectified fpirit: 
they become mifciblewith water into a milky liquor, by 
the mediation of the yolk or white of an egg, and more 
elegantly by mucilages. Diftilled with water, they yield 
a fubtile penetrating eflentia! oil, vulgarly called J'pirit of 
turpentine; a yellow or blackifti refin remaining in the 
(fill, which is the common rofin of the (hops. The effen- 
tial oil, on being diftilled in a retort, becomes more fub- 
tile, and in this ftate is called ethereal oil of turpentine. 
The turpentines ftimulate the firft'paffages, and prove 
laxative; and we are told by Dr. Cullen, that half an 
ounce or an ounce of Venice turpentine, triturated with 
the yolk of an egg, and diffufed in water, may be em¬ 
ployed in the form of an injeflion, as the moll certain 
laxative in colics, and other cafes of obftinate coftivenefs. 
When turpentine is carried into the blood-veffels, it fti- 
mulates the whole fyftem; hence its ufe in chronic rheu- 
matifm and paralyfis. It readily paffes off by urine, 
which it imbues with a peculiar odour; alfo by perfpira- 
tion, and probably by exhalation from the lungs; and to 
thefe refpeftive effeffs are to be aferibed the virtues it 
may poffefs in gravelly complaints, feurvy, and pulmo¬ 
nic diforders. In all thefe difeafes, however, and efpe- 
cially the laft, this medicine, as well as fome of the gums 
and balfamsof the terebinthinate kind, by affing as fti- 
mulants, are often produflive of mifehief, as w'as firftob- 
ferved by Boerhaave, and fince by Fothergill. 
Theelfential oil, in which the virtues of turpentine re- 
fide, is not only preferred for external ufe, as a rubifa- 
cient, &c. but alfo internally as a diuretic; and by Pit- 
cairne and Cheyne, as a remedy for the feiatica ; but few 
(tomachs are able to bear it in thedofes they direCl. Tur¬ 
pentine, fo much ufed formerly as a digeftive application, 
is in modern furgery almolf wholly exploded. 
Befides this well-known produCt, the larch yields alfo a 
tnanna and a gum. The manna is found in the fouth of 
France, and is called there Mamie de Brianfon ; it is white, 
concrete, and fweet, like fine new honey. It is rare, and 
met with only in fmall drops, fo that it would be very dif¬ 
ficult to collect a pound of it. The drops are more or 
lefs hard, and adhere to the leaves. Monf. Villars having 
made fome enquiries relative to this fubftance, with Monf. 
Guettard, in the year 1773, found it at fun-rife almoft 
fluid, and picked up drops of it on the turf exaftly like 
thofe which remained on the trees; but they have not 
given any analyfis or farther account of it, except that 
the feafon of 1773 was lefs productive of manna than 
ufual. Pallas informs us that they have this manna in 
the Ruffian empire, but that it is rarely found concrete, 
being commonly foon wafhed off by the rains which are 
frequent on the Uralian mountains. He remarks alfo, 
that the turpentine refides in the bark and the wood next 
to it, as is apparent when the trunk of a larch is fawed 
tranfverfely; for then it may be feen that the inner wood 
for more than half the diameter is dry. It cannot, there¬ 
fore, be of any ufe to drive the auger almoft to the centre 
of the tree, as Dr. Anderfon recommends. 
Pallas alfo mentions a gum that is yielded by the larch 
in particular circumftances. When the woods are on fire, 
which frequently happens in Ruffia, the larches are eafily 
burnt on the fide next the flame to the height of feveral 
feet, on account of the turpentine in which they abound. 
If the wood happens to be fcorched to the pith, the in¬ 
ner 
