220 pine. 



tember. After the outer bark has been removed, the inner bark and a 

 thin slip of the wood are cut off, and a wound is made with a sharp tool 

 about three inches square by an inch deep. The resinous juice soon begins 

 to exude, and runs down the trunk into a trough placed to receive it. This 

 is called pure dipping, (Terebinthine brute, Fr.,) while the juice which con- 

 cretes in the wounds is called galipot or barras. 



Oil of Terpentine is obtained by distilling the galipot with water in a 

 common still, when the oil is found in the receiver swimming on the water, 

 from which it is easily separated ; the average proportion is 60 pounds of 

 oil from 250 pounds of good turpentine. When rectified, it is called spirits 

 or essential oil. 



Common or Yellotc Resin is the residue of the distillation of the essential 

 oil. When the process is performed without the addition of water, to 

 dryness, the produce is deeper coloured and transparent, and is designated 

 black or common resin or colophony *: but when agitated with water while 

 yet fluid, it is named yellow resin. A similar and preferable kind of resin 

 is made by melting and agitating the galipot in water. 



Tar, (PLv Uquida, Ph. — Goudron, Fr.,) is obtained by a kind of distil- 

 lation from the wood and roots of this pine, which is cut into billets, and 

 then placed in a conical cavity dug in the ground and piled up in a stack 

 which is covered with turf. Fire is then applied to the wood, and it is suf- 

 fered to burn slowly ; during this process the tar is formed, and runs off at 

 the bottom of the pile into a channel cut for the purpose, and is then col- 

 lected in barrels. Much of the tar imported into England is brought from 

 the Baltic. The process for obtaining tar at the present day differs but 

 little from that pursued by the ancient Macedonians as described by Theo- 

 phrastus (Lib. TX. c. 3.) It was probably obtained likewise from other 

 species of pine. 



Pitch, {Pit inspissata, Ph. — Brais-gras, Fr.,) is made by melting coarse 

 hard resin, or brai-sec, as it is called in France, with an equal quantity of 

 tar, in large copper vessels. If the process of inspissation be carried to its 

 utmost limit, the pitch becomes hard and dry, and is designated Pix arida, 

 which is used only externally. 



Qualities. Turpentines, although procured from various 

 species of the pine tribe, agree in general and chemical pro- 

 perties. They are semi-fluid, transparent, tenacious, combine 

 readily with fixed oils, are very inflammable, and emit much 

 smoke. They are insoluble in water, but soluble in alcohol 

 and ether. They contain essential oil, succinic acid, and resin. 



" Oil of Turpcyitine has a strong, penetrating, peculiar odour, 

 and a hot, pungent, bitterish taste. It is perfectly limpid and 

 colourless, extremely light, volatile, and inflammable ; its boil- 



* Colophonia was a name given by the ancients to a raw liquid resin 

 brought from Colophon in Ionia, and is described by Dioscorides {Mat. 

 Med. lib. i. c. 02.). 



