Production of Turpentine, etc. 199 



790. The following recipe is from DIngler's Polytechnic Journal, 

 and is intended for piles and posts : " Take 50 parts of rosin, 40 of 

 finely powdered chalk, 300 (more or less) of fine white sharp sand, 

 4 of linseed oil, 1 of native red oxyde of copper, and 1 of sulphuric 

 acid. First heat the resin, chalk, sand, and oil, then add the oxyde 

 and with care the acid ; stir carefully, and apply as a paint while 

 still hot. If not liquid enough, add oil." This coating when cold 

 and dry is very hard, and it is claimed to be very durable. 



CHAPTEE XIX. 



EESINOUS AND OTHER PRODUCTS OF CONIFEES. 



Naval Stores. 



791. This term, as used in commerce, includes the several resinous 

 products of pine forests, and particularly the oil or spirits of turpen- 

 tine,- distilled from crude turpentine ; rosin, or the solid residuum of 

 this distillation ; tar, obtained by the combustion of resinous woods 

 or refuse materials, containing resin, in smothered fires, or their ex- 

 posure to heat externally applied, and pitdi, which difiers chiefly 

 from tar in being solid when cold. 



792. Formerly, crude turpentine was an article of commerce, and 

 its distillation was carried on in large establishments near the cen- 

 ters of trade ; but in recent years local distilleries have been erected 

 near the forests where the raw material is. collected, and the products 

 are sent to market prepared for use. 



The Produetion of Turpentine and other Resinous Materials. 



793. When we cut through the bark into the outer wood of a 

 pine, a fir, or a spruce tree," in the spring or early summer, there 

 slowly exudes from the wound a viscid and at first colorless and 

 transparent substance, known in the pine as ' ' turpentine." Upon ex- 

 posure to the air, it absorbs oxygen and becomes whitish, opaque, and 

 solid. When distilled with a little water, the volatile portion passes 

 off with the vapor, and when condensed, it separates and becomes 

 a limpid, volatile, and strongly scented liquid, known as the spirits 

 of turpentine. The portion not volatile, and remaining in the still, 



1 The Taxus does not have resiniferous canals in its wood. They are found 

 in the genera Cedrits, Abies, Pinus, Larix,. Picca, Pseudolarix, Thuja, Pinus, 

 Cimressus, IHotiu, Aravcaria, etc., hoth in the root and stem. 



