80 



almost as much a luxury at the table as a valuable article of medicine. By what particular principle in the 

 licpior its power of preventing and subduing scorbutic complaints is effected, or whether this efficacy be not 

 the result of the general preparation, does not appear to be as yet determined; but, as simple decoctions and 

 infusions of the branches of several species of Pinus have been found conducive to the same purposes, it is 

 most reasonable to suppose that the spruce alone is the essential part of the medicine. Some authors have 

 imagined the salutary properties of medicines of this sort to consist in their gently increasing the secretions 

 fi'om the kidnies; whilst otiiers have contended for a peculiar power in the vegetable acids to promote venous 

 absorption. Whatever be the modus operandi, however, the acid contained in infusions of fir, and which has 

 been called Acidiim Abietis, has been found, when exhibited by itself, to act as a diuretic," and, though the 

 properties of this acid may be no way different from those of others extracted from vegetable substances^ it 

 is highly probable that this is one of the most active principles in terebinthinate infusions. 



THE LARCH 



LIQUID RESIN. 



fResina liquida LarignaJ. Largatiim of the Italians. 

 Terehinthina Veneta. Pharm. Ed. 

 Venice Turpentine. 



Tnis resin is by most writers, and in the shops, esteemed the best (after that of Pistachia Terebinthus) 

 of those juices commonly called Turpentines. It is usually thinner than any other sort, of a pale yellowish 

 colour, and of a hot, pungent, bitterish taste. The smell is strong, and far from being agreeable. Though 

 it bears the name of Venice Turpentine, very little of it is exported from the Venetian territories- but it is 

 probable that the merchants of that country were the first who substituted it for the genuine Turpentine of 

 Cyprus. That which is most commonly met with in the shops comes from New England; from what tree 

 we are uncertain. The true liquid resin of the larch is obtained chiefly from France and Germany. 



The extraction of the juice of the Larch is performed by boring holes, of about an inch in diameter, and 

 with a gentle descent outwards, in the most knotty parts of tlie tree, proceeding from the height of two 

 inches above the ground to ten or twelve. The south side is generally preferred, on account of the sun's heat 

 facihtating the flow of .the juice. There are adapted to the holes what maybe called gutters, which are 

 fifteen or twenty inches in length, and terminate hke pegs perforated in the centre. The juice passino- alono- 

 these tubes falls into troughs placed at their most depending 'part. The result of the process is carefully 

 examined every morning and evening, from the end of May (which being the time at which the trees are 

 fullest of sap, is also that at which they are generally perforated) to the end of September. As soon as the 

 supply appears to diminish, the holes to which the gutters were attached are stopped up with peo-s for about 

 a fortnight, after which interval they are opened again, to discharge the re-collected resin. This operation 

 is repeated until the tree being drained furnishes but a very small quantity of juice; the pegs are then replaced, 

 and not withdrawn until the succeeding season. As it is impossible to secure the troughs from leaves, and 

 other extraneous matter which will mix itself with the fluid, the latter is usually strained throuf»-h a hair sie 

 into other vessels, in order to be transported to the places of sale. It is only from the most healthy and 

 vigorous trees that the resinous juice is obtained; those which are too young or too old produce only a small 

 quantity, though at all ages tears of this substance may be seen on various parts of the trees, and especially 

 where knots exist. Some of the mature trees (Haller says') will discharge five pounds of juice in a year. 

 The resin seems to reside in the exterior circles of the wood, for, if the healthiest part of the tree be cut ijito 

 billets, there are often found, at the distance of five or six inches from the inmost part, depots (as it were) 

 of this resinous matter, which are sometimes an inch in thickness, three or four inches in width, and as many 

 or more, in length. In a tree thirty or forty years old, it very frequently happens that five or six of these 



sieve 



** The late Dr. Hope made frequent trial of this acid in the Royal Infirmary of Edinburgh, and conceived it to be beneficial in obstinate couo-hs 

 and catarrhs. (See Lewis's Mat, 'Med. Art. Abies.) " Siirp. Indig. Ilelv. Tom, 2. p. 314. 



