as it runs from the kiln. After the kiln is marked out, they bring the wood, ready split up, in small billets, rather smaller than are generally used for the fires in England, and it is then packed as soon as possible, with the end inwards, sloping towards the middle, and the middle is filled up with small wood, and the knots of trees, which last have more tar in them than any other part of the wood. The kiln is built in such a way, that at twelve or fourteen feet high it will overhang two or three feet, and it appears quite compact and solid. After the whole of the wood is piled on, they get a parcel of small logs, and then place a line of turf, then another line of logs, and so on alternately all the way up, and the top they cover with two or three thicknesses of turf. After the whole is covered in this way, they take out a turf in ten or a dozen different places round the top, at each of which they light it, and it then burns downwards till the whole of the tar is melted out; and if it burns too fast they stop some of the holes, and if not fast enough they open others, all of which the tar-burner, from practice, is able to judge of. When it begins to run slow, if it is near where charcoal is wanted, they fill up all the holes, and watch it, to prevent the fire breaking out any where till the whole is charred. The charcoal is worth two-pence or three-pence, British sterling, per bushel. It will take six or eight days to burn a tar-kiln; in some places they burn it at such a distance from the shipping, that they have very far to roll it, and even then sell it at from three and sixpence to five shillings, British sterling, per barrel, sometimes taking the whole out in goods, but never less than half the amount in goods; from all which it will be reasonably supposed that tar-burning in that country is but a bad trade, as it must be a good hand to make more than at the rate of a barrel a day; the barrels cost the burner about one shilling and threepence, British sterling, each: the tar-makers are in general very poor, except here and there one, that has an opportunity of making it near the water-side.

"Pitch is made by either boiling the tar till it comes to a proper thickness, or else by burning it; the latter is done by digging a hole in the ground, and lining it with brick; it is then filled with tar, and they set fire to it, and allow it to burn till they judge it has burnt enough, which is known by dipping a stick into it, and letting it cool; when burnt enough they put a cover over it, which stops it

close, and puts out the fire. Five barrels of green tar will make two of pitch; and it will take two barrels of other tar to make one of pitch."

The turpentine thus obtained is loaded with impurities, from which it is freed by two distinct methods. One consists in inclos-. ing it in a cask perforated at bottom, when, by exposure to a hot sun, it becomes so fluid as to filter through, which gives the finest and most valued turpentine. The other method consists in heating it moderately in a large copper, till it is quite liquid, and then filtering it through a strainer made of rows of straws laid close to each other. This gives it a golden colour.

The essential oil of turpentine is prepared largely both in the countries where the turpentine is extracted, and from turpentine imported to our own coasts. The process is as follows: An alembic with a worm and cooler is used, precisely of the same construction as what is employed for the distillation of spirits: this is filled with turpentine and water in due proportions, and the volatile part, after distillation, is found to consist of oil of turpentine swimming on the water. This oil is perfectly limpid and colourless, has a very strong smell, a bitterish taste, is extremely inflammable, and has all the properties of the other essential oils. It is employed in immense quantities in a variety of varnishes and similar preparations; but for the finer purposes, such, for example, as that of dissolving gum copal, it is necessary to rectify it by a second distillation with water in a still, using a very gentle heat, and keeping apart the first product, which is the best. From 250lb. of good turpentine the oil obtained is about 60lb.

Common, or yellow rosin, is the brittle and opaque residue from the distillation of the oil of turpentine. It is called by the French braisec; who also obtain it from the hard concrete turpentine that forms about the incisions of the fir-trees, while exuding. When common rosin is boiled in water for a time, it becomes yellow and transparent; and is then the rosin used by musicians for the bows and strings of violins. When common rosin is kept in fusion for a considerable time it becomes of a browner colour; is still harder and less adhesive to the fingers when cold, and is then called black rosin, or colophony; and this is the ultimate point to which the inspissation of turpentine is carried.

A very fine essential oil is obtained in some parts of Germany by

distillation of the green tops and cones of the stone-pine (pinuslembra), which is known in medicine by the name of oleum templinum, or popularly, krumholzoel. It is somewhat greenish, or sometimes of a golden yellow, very fragrant and aromatic.

True Burgundy pitch is a kind of rosin prepared in great quantities in the neighbourhood of Neufchatel, from the Norway spruce fir. The turpentine of this fir is peculiarly thick, and hence concretes around the incisions without flowing down. It is in this manner picked off, and when a sufficient quantity is collected, it is put with water into large boilers, melted, and then strained under a press, through close cloths, into barrels, in which it is transported for sale. Burgundy pitch, thus procured, is a brittle, opaque, light yellow, or sometimes reddish brown rosin, of such consistency that it will barely soften by the heat of the human body; and is hence much used in plaisters. This substance is also sometimes obtained from the larch.

The rosin called frankincense is supposed to exude spontaneously, and not by incision, from the Norway spruce, and to undergo no preparation. It is brittle, in small roundish masses, of a brownish yellow on the outside, and white internally. It possesses the common properties of the turpentines, and has a very pleasant smell when burnt. Ants, for some unknown purpose, collect this substance, which is found in pieces throughout their nests or hills, and was at one time supposed to be a secretion of their own, and hence distinguished by the name of electrum formicarum, as it was by that of wild frankincense, thus Germanicum, suffimentum silvestre.

All the turpentines in medicine have been considered as hot, stimu. lating corroborants and detergents; qualities which they possess in common. They stimulate the stomach, and prove laxative; when carried into the blood-vessels they excite the whole system, and thus render themselves serviceable in chronic rheumatism and paralysis. Turpentine readily passes off by urine, which it imbues with a peculiar odour; also by perspiration and by exhalation from the lungs : and to these respective effects are ascribed the virtues it possesses in gravelly complaints, scurvy, and pulmonic disorders. Turpentine is much used in gleets and fluor albus, and in general with much success. The essential oil, in which the virtues of the turpentine reside, is not only preferred for external use as a rubefacient, but also internally as a diuretic and styptic; the latter of which qualities it pos

sesses in a very high degree. Formerly turpentine was much used as a digestive application to ulcers, &c. but in the modern practice of surgery it is almost wholly exploded.

[Pantalogia.

SECTION XIII.

Canadian Balsam Tree.

Pinus balsamea.-LINN.

Carpathian, or Hungarian Balsam.

Pinus lembra.-LINN.

THESE We have already noticed in the preceding section, as the resinous juice, or liquid turpentines of the balm of gilead fir, and the stone pine. The former is mostly in use, and from being less offensive to the stomach, may often with great benefit supersede the use of the balsam of Copaiva. It is transparent, of a light amber colour, and tolerably firm consistence. It is imported into our own country from Canada, whence its name.

[EDITOR.

SECTION XIV.

Balsam of Peru Tree.

Myroxylon Peruiferum.-LINN.

Or this genus there are three species, and all natives of South America. The chief is that before us. It is a native of Peru, Brazil, Mexico, and Terra Firma, with a smooth, thick, resinous bark, and leaves abruptly pinnate, in double pairs. This tree was not botanically characterised till the year 1781, when a specimen of it was sent by Mutis, from Terra Firma, to tire younger Linnæus, who has described it in the Supplementum Plantarum, under the name of Myroxylon peruiferum. Its synonyms are Hoitziloxtil, and Cabureiba *.

Two kinds of this balsam are imported here the common or black, and the white. The first, which is chiefly used, is about the consistence of a syrup, of a dark opake reddish brown colour, in.

* Hernand. Thes. Rer. Med. Nov. Hisp. Pis. Ind. Hist. Nat. et Mes.

clining to black, and of an agreeable aromatic smell, and a very hot pungent taste.

Balsam of Peru is a very warm aromatic medicine, hotter than any of the other natural balsams; hence, in cold phlegmatic habits, it has been given to warm the constitution, strengthen the nervous system, and attenuate viscid humours. It has been also used by surgeons in certain wounds and ulcers.

The white balsam of Peru, or white storax, is brought here in gourd shells, and is of a pale yellow colour, thick, and tenacious, becoming by age solid and brittle.

This balsam is less hot than the former, but of a more agreeable fragrant smell, approaching somewhat to that of storax.

[Mutis. Woodville. Zea.

SECTION XV.

Balm, or Balsam of Gilead Tree.

Amyris Gileadensis.-WooDv.

Or this valuable genus nineteen species have been collected in Asia, Africa, and America, almost all of which produce a considerable quantity of terebinthinate rosin or balsam, and several of them of a very grateful taste or flavour. The following are chiefly worthy of notice. 1. a. elemifera, yielding the officinal gum-elemi; 2. a. gileadensis, balsam of Gilead-tree, balsam of Mecca, or Turkey-tree, so called from its yielding this gum; 3. a. toxifera, poison ash, yielding a liquid gum as black as ink; 4. a. balsamiferarosewood; an elegant and odoriferous Jamaica tree, of late much and deservedly esteemed by our cabinet-makers. A. toxifera, though poisonous to animals in general, affords a fruit that is nutritive to one or two species of the loxus or grosbeak, which feed on it with great glee.

The vernacular name for the Amyris Gileadensis, or Balm of Gilead Tree, according to Bruce, is Bilessan. It grows to the height of fourteen feet: its branches are numerous, spreading, crooked: the wood is white, soft, and covered with a smooth ashcoloured bark: the leaves are small, few, commonly consisting of one pair of wings, with an odd one at the top: the wings are ses