March 1, 1865.] THE TECHNOLOGIST. 



TURPENTINE AND RESIN. 375 



A well-regulated tapping may last 150 years and more, especially if 

 the precaution be taken in the first years, whilst the tree is still weak, 

 to give a year's rest after each period of extraction of seven or eight 

 years. 



Sometimes, when the tree is vigorous enough to bear it, two incisions 

 are made at a time — a high " quarre " and a low " quarre," or " basson." 

 Lastly, instead of opening the channels side by side, they are put as 

 opposite to each other as possible, the new ones in the centre of the 

 intervals which separate the old ones. 



The tapping, when managed so as to preserve the vitality of the 

 trees, is called " life-tapping." If, however, the pine is to be exhausted 

 in a short time, none of these precautions are observed ; they are cut 

 on all sides, the channels being carried in one year to treble the 

 height, and this is called " lost pine " or " tapped to death." To 

 reach up to the height which the channels attain, a pole with notches 

 on opposite sides is used by the operator. The tapping is begun in 

 May and continued to the end of September ; the turpentine flowing- 

 out collects in the troughs, whence it is removed from time to time. 

 A good workman can notch 200 to 300 trees a day. 



A strong and hardy pine, standing isolated, will produce from fifty 

 to 100 lbs. of the raw material in the year, but trees growing in clumps 

 ■will not yield more than twelve or fourteen pounds. The pines of the 

 downs of Gascoigne are much more productive than others ; those of 

 the " Provence," wdiich were submitted to a similar treatment, did not 

 give any such satisfactory results. 



The gross proceeds or raw products from tapping are of three kinds : 

 — First, the soft resin, or liquid part, which has collected in the 

 troughs ; secondly, the " Galipot " resin, solidified in the grooves or 

 channels, and which may be detached in pieces without being mixed 

 with particles of the bark ; thirdly, the " Barras," which must be 

 scraped off", and is only an impure galipot, mixed with slices and 

 fragments of bark, &c. 



All these products are formed of essence of turpentine, and of resin 

 or colophony; they only differ in the proportion. of the two elements. 

 Industry purifies, manipulates, and mixes them in the most varied 

 processes, and manufactures them into a multitude of substances, of 

 which the principal are — 



1st. Pastes of turpentine, viscous liquids extracted from the raw 

 materials by means of a low artificial heat filtering through straw 

 hurdles (common turpentine paste), or by exposure to solar heat upon 

 inclined planes, formed of boards badly joined together (fine sun 

 turpentine paste). 



2nd. The essence or oil of turpentine, a colourless liquid of slight 

 oleaginous substance, produced by distillation of the soft resin or 

 turpentine pastes. 



3rd. The dry resin, or colophony, the residue of the distillation of 

 vol. v. s s 



