84 VEGETABLE SUBSTANCES. 



of pine; and, having; covered them with turf, they 

 were suffered to burn in tlie same smothered manner ; 

 while the tar, meltino-, fell to the bottom of the stack, 

 and ran out by a small channel cut for the purpose." 



From the larch is obtained what is called Venice 

 turpentine : it is procured by incision into the tree; 

 and from it the transparent oil of turpentine is dis- 

 tilled. The larch yields a gum and a manna ; and a 

 species of fungus that grows upon it in Siberia has a 

 rind which the natives make use of in dyeing red ; 

 while the body of the fungais is used as a soap. The 

 common, or Strasburgh turpentine is obtained chiefly 

 from the silver fir ; Burgundy pitch from the spruce ; 

 and Canada balsam, the purest of all the jjine tur- 

 pentines, from the balm of Gilead fir. Turpentine of 

 highly aromatic flavour, called in commerce Chian 

 turpentine, is also derived from the turpentine-tree, 

 (Pistacia terebinthus,) — a native of Barbary and the 

 south of Europe, — which is a tree belonging to ano- 

 ther family, and quite different in appearance from 

 the pines. 



Turpentine, from what species soever of the pine it 

 is derived, can be dissolved in rectified spirit or pure 

 alcohol; and, by distillation, they all give similar 

 oils, which, from their being distilled, (and not from 

 any resemblance to alcohol, or spirits properly so 

 called,) are vulgarly termed spii-its of turpentine. If 

 the distillation be performed with water, the product 

 is an essential oil, the common spirit of turpentine ; 

 and, if the distillation be carried on in a retort, without 

 water, the product is more volatile and pvmgent 

 — a concentrated oil as it were, — and is called the 

 etherial spirit of turpentine. The residuum that is 

 left, in both cases, is a brownish resinous mass, 

 brittle, capable of being melted, highly inflammable,, 

 insoluble in water, but mixing freely with oils : it is 

 the common rositi of commerce. 



Beside producing these resins and oils, there are 



