484 
P I N U S. 
The refinous fubftance at this time, being much heated, 
becomes more fluid; and, the air being expanded through 
the whole exterior texture of the plant, the juice is preffed 
upward by the fame means and force as in other plants. 
Though the afliftance of the leaves is comparatively trifling, 
their deficiency is fupplied by the very expanfive quality 
of the juice ; a quality it poffeffes to fuch a degree, that 
in barrelling tar at Archangel, it is found neceflary to 
leave a confiderable fpace in the top of the barrel empty, 
I have been told as much as four or five inches, in order 
to meet the expanfion of our temperature. 
When by a high temperature the juice of the tree, or 
rather the oil, is forced off in various ways, as at any am¬ 
putated branch or wound in the tree, by the buds and 
leaves, &c. on the return of the evening the refinous 
matter congeals, and fixes itfelf in the fituation where it 
happens to be, with a very little decline of the tempera¬ 
ture, and becomes almoft incapable of being raifed any 
higher by the power of capillary attraction. In confe- 
quence of the oily fubftance being driven off by the heat 
of the day, and the veffels becoming comparatively 
empty, they are then compelled to abforb more than an 
ordinary portion of the circumambient atmofphere, not 
only to reftore the Juccus communis that the tree had per- 
fpired in the heat of the day like other plants, but like- 
wile to fill up the fpace before occupied by the volatile 
oil of the Juccus propriu s. 
Thus the fir-tree, in a warm climate, is not only liable 
to be deprived of its native juices, by one part, which ap¬ 
pears to be about twenty-five per cent, of the whole juice, 
being driven off in oily vapour, and another rendered 
thick and pitchy, fo that it is incapable of being afted 
upon any more in the fliape of fap; but likewife to be 
loaded with matter, to fill the fpace before occupied by 
the volatile oil now diflipated. This, coming in fome 
meafure into contadt with the refinous fubftance by the 
returning heat of another day, extraCfs from it fomething 
like the film that will appear on the furface of water im¬ 
pregnated with refin or pitch ; and thus the native juices 
are rendered folid and hard. Hence the lower or but 
ends of fir-trees, the growth of this country, are frequently 
found as hard and full of refin as if they had been fatu- 
rated with it in a boiling caldron; while the trunk and 
the branches have no more than is abfolutely neceflary to 
conftitute the woody fibres, which become very dry and 
brittle. When fuch trees are cut down for purpofes of 
carpentry, they are found very difficult to work. In the 
firft inftance, the lawyers experience difficulty in cutting 
them. They are not only hard, but they clog the faw, 
filling up the teeth, while a refinous matter adheres to the 
iides of even the beft faws. When, after confiderable 
trouble and expenfe, they are cut into planks, the fame 
effedl is found on the carpenter’s tools ; the edge, however 
fine, being very foon clogged up; fo that, if the work be 
fmall, it is fcarcely poflible to make fine tools work at all, 
without a very large portion of hog’s lard, or fome other 
greafe. This caufies the difficulty of working firs of 
Britifli growth; and is wholly occafioned by the oily part 
of the juice being driven off: for, if the workmen apply 
oil of turpentine to their tools, it is found the beft for 
their purpofe, though moft expenfive ; and this is the very 
matter of which the timber is deprived by a high tempe¬ 
rature. 
In this country, or perhaps any other of equal tempe¬ 
rature, if a great number of fir-trees, or even fmall clumps 
of them, be planted together on any plain, for ornament 
or ufe, where there is no flielter from one fide more than 
another, they are generally found to thrive beft on the 
north fide of the clump. The reafon is, that thofe on the 
fouth fide flielter them from the direct rays of heat, though 
the heat or general temperature of the day may be nearly 
as high cn the north as on the fouth fide. A few in- 
ftances of this fail near London may be mentioned. In 
the whole of thofe clumps on Hounflow-heath, where the 
trees are not deftroyed, but grow fo as to flielter each 
other, and in that other clump on the high ground fouth 
of the fame road, between Egham and Virginia Water; 
although the trees are all young, there are feveral feet dif¬ 
ference in the height between thofe on the north and 
thofe on the fouth fide of the fame clumps. 
Hence it is inferred, that no fpecies of the fir-tree will 
arrive at fuch perfection in our country, on account of its 
high and rapid change of temperature, as in the higher 
latitudes. Yet nature is bountiful in providing for all; 
as the reverfe of this is the cafe with the oak-tree. 
22. Pinus balfamea, the balm-of-Gilead fir-tree: leaves 
folitary, flat, emarginate, fubpeCtinate, almoft upright 
above; fcales of the cone, when in flower, acuminate re¬ 
flex. This beautiful tree rifes with an upright ftem. 
The leaves are dark-green on their upper furface, and 
marked with whitilh lines underneath. The cones are 
roundifti and fmall. The buds and leaves are remarkably 
fragrant. From wounds made in this tree a very fine tur¬ 
pentine is obtained, which is fometimes fold for the true 
balm of Gilead. The balm-of-Gilead fir has very much 
the habit of the filver fir, but the leaves are wider and 
blunter, difpofed on each fide along the branches like the 
teeth of a comb, but in a double row, the upper one 
fhorter than the under; underneath they are marked with 
a double glaucous line, and each has eight rows of white 
dots; they are often cloven at top. It was formerly 
growing (1696) in the bifhop of London’s garden at 
Fulham; and of late years a great number of the trees 
have been raifed from feeds brought from Virginia, where 
it is a native. It makes very little progrefs after eight or 
ten years growth; the only place in which the trees have 
made any figure is at the duke of Bedford’s, at Woburn, 
in Bedfordlhire. 
This is a very common tree in both the provinces 
of Upper and Lower Canada. This tree never grows 
to a very large fize. There arile blifters on the 
ftem of the tree, which the Indians cut open in 
the winter, and colled the balfam. It has been faid that 
the balfam is colleded from the root of the tree, but that 
is not the cafe. The Indians ufe the balfam to frefh 
wounds : it feems to have the fame virtues as the balfam 
copaiba. The dofe is generally from twenty-five to forty- 
five drops. It is exported in fmall quantities; can be 
procured in great quantities, and might be made an article 
of commerce. The American Indian name of this tree 
is otjhogoton. 
23. Pinus Canadenfis, the hemlock fpruce fir-tree ; 
(onenta of the American Indians:) leaves folitary, flat, 
lubmembranaceous, (harpilh, pediinate; cones ovate, 
fcarcely fliorter than the leaf. The hemlock fpruce-fir is 
a beautiful but delicate tree, and mull have a good foil, 
with a warm fituation. It will be improved by tying its 
leading Cioot to a (take annually as it advances. The 
cone is of the fize and fliape of a fmall hen’s egg, the 
whole is of an afli-coloured bay. Scales coriaceous, 
thick, triangular, the outer fide rounded and fomewhat 
crenulate. Nuts a little fmaller than in the black fpruce, 
with a winged membrane on the outer fide only. Seed 
ovate, acuminate downwards. Embryo like that of the 
black fpruce in fituation and lhape, but with four coty¬ 
ledons. It is a native of many parts of North America; 
but does not thrive well in any part of England, where it 
was introduced in 1736 by Peter Collinfon, efq. The 
American Indians ufe a decoftion of the branches in the 
rheumatifm and in colds; and the inner bark or the root 
they dry and pulverife, and ufe the powder in venereal 
ulcers 5 taking at the fame time a quart or three pints, in 
the twenty-four hours, of the Indian decoftion, until the 
cure is effected, which is generally in three weeks or a 
month. “It is aftonifliing what cures I have feen made 
in the fyphilis, without the fmalleft ufe of mercury. I 
have feen the perfons fo cured ten years afterwards, and 
no fecondary complaints had then made their appearance; 
and thofe perfons enjoyed good health. Not an article of 
commerce.” The medical remarks on this and the pre¬ 
ceding 
