March 1, 1865.] THE TECHNOLOGIST. 



TURPENTINE AND RESIN. 373 



old will yield annually from 3 to 5 kilogrammes of turpentine ; and 

 this for five or six successive years, if the channels or incisions made 

 are carefully plugged or closed in winter. 



The pursuit is followed in Valais by the Lombardians, who traverse 

 the forests yearly to exercise their industry. It is not much practised 

 in France, at least with less regularity. 



The leaves of this tree exude a particular resinous substance, in the 

 shape of small white grains, which are used medicinally as a purgative, 

 under the name of Manna of Briancon. 



Pinus Laricio, Poir.— This pine has only of late years been much em- 

 ployed for turpentine ; but attention is now being generally directed 

 to it, and this industry is established on a definite scale in Corsica. Ee- 

 sin was first extracted from the Corsican tress in 1856. In 1863, 175,000 

 trees (laricio and maritime pines) were subjected to tapping. Two 

 kilogrammes (about 4 J lbs.) of resin were considered as the probable 

 average yield of each tree ; but this estimate, it is thought, will be con- 

 siderably exceeded, as the Corsican pine proves to be much richer in 

 resin than was anticipated. Still, this extraction of resin accordirg to 

 M, Tassy, the Conservateur of Forests, must always remain of secon- 

 dary importance, and should only be carried on in forests which are 

 difficult of access. Even if the quality of the trees is not injured by the 

 tapping, there is reason to believe that their growth is impeded. 



The composition of the forests of Corsica is stated to be as follows : 

 —Of 45,810 hectares belonging to the State, 34,350 are covered with 

 resin-yielding trees, of which the P. Laricio predominates. Of 57,428 

 hectares belonging to the communes the laricio and maritime pines are 

 predominant in one-half. 



The Austrian pine may be operated on with advantage ; the 

 turpentine contains in the proportion of 1 spirit to 3^ of resin. The 

 trees which have been tapped for six or eight years yield better products 

 than those which have been recently operated on. From trees of 

 about thirty centimetres in diameter a mean annual yield of four 

 kilogrammes of crude turpentine is obtained. 



Pinus Jialepensis, Mill. — In Provence this pine is tapped in the same 

 manner as the maritime pine is in the west, and the same products are 

 obtained, but of less value. In general the tree is tapped when it has 

 attained the dimensions of twenty or thirty centimetres in diameter. 

 If properly attended to, it will yield for fifteen or twenty years six or 

 seven kilogrammes of turpentine annually per tree. The notches 

 which are made in the bark to induce the flow of the sap are about ten 

 centimetres wide, and are called " Surles." Every fifteen days the flow 

 is invigorated by a small fresh cut at the upper part, until, in the 

 course of the year, the incision or notch reaches the length of thirty 

 centimetres. The turpentine is received in holes opened in the earth 

 at the foot of the tree. It is known under the name of " Perinne 

 vierge." After preparing and cooling in cakes, the resin so obtained 



