OF FOREST-TREES. 



319 



Of tar, by boiling it to a sufficient height, pitch is made ; and in some qu xxu 

 places where resin is plentiful, a fit proportion of that may be dissolved in ^^^"^v^^^ 

 the tar whilst it is boiling, and this mixture is soonest converted to pitch; 

 but it is of somewhat a differing kind from that which is made of tar 

 only, without other composition. There is a way, which some ship- 

 carpenters in those countries have used, to bring the tar into pitch for any 

 sudden use, by making the tar so very hot in an iron kettle, that it will 

 easily take fire, which when blazing, and set in an airy place, they let 

 burn so long, till, by taking out some small quantity for trial, being cold, 

 it appears of a sufficient consistence : then by covering the kettle close, 

 the fire is extinguished, and the pitch is made without more ceremony. 

 There is a process of making resin also out of the same knots, by splitting 

 them out into thin pieces, and then boiling them in water, which will 

 educe all the resinous matter, and gather it into a body, which, when 

 cold, will harden into pure resin. It is moreover to be understood, that 

 the Fir, and most coniferous trees, yield the same concretes, lachrymee, 

 turpentines, resins, hard, naval or stone, and liquid pitch, and tar for 

 remedies against arthritic and pulmonic affections : These the chirurgeon 

 uses in plasters, and they are applied to mechanic, and other innumerable 

 purposes. From their fuliginous vapour, raised by burning, especially the 

 resin, we have our lamp and printers' black. I am persuaded the Pine, 

 Pitch, and Fir-trees in Scotland might yield his Majesty plenty of 

 excellent tar, was some industrious person employed about the work. 

 I wonder it has been so long neglected. 



Other processes for extracting of these substances may be seen in 

 Mr. Ray's History of Plants, already mentioned, lib. xxix. cap. i. And 

 as to pitch and tar, how they make it near Marseilles, in France, from 

 the Pines growing about that city, see Philosophical Transactions, 

 No. 243, p. 291, anno I696, very well worthy the transcribing, if what 

 is mentioned in this chapter were at all defective. 



I had, in the former editions of the Silva, placed the Larix among the u a k i x. 

 trees which shed their leaves in winter, as indeed it does, but not before 

 there is almost immediate supply of fresh ; let it, therefore, from 

 its similitude, stature, and productions, challenge rank among the 

 coniferous. We raise it of seeds, and it grows spontaneously in Stiria, 

 Carinthia, and other Alpine countries. The change of the colour of the 



