[08 PRESEIIVATION OF TI3IBE::. 



the wood, which they are to preserve, is not kept constantly wet. 

 Solutions of common salt, of chloride of lime, the mother-water of 

 salt-marshes, &c., were all tried and found useful : casks, the wood 

 of which had been prepared with the chlorides, after having been 

 long kept in very damp cellars, came out as fresh as those which 

 had been impregnated with the pyrolignite of iron ; the flexibility of 

 the wood preserved with these alkaline and earthy salts was further 

 as great as at the beginning of the experiment. 



Having now come to a concUision in regard to the substances 

 most effectual in preserving wood, the next business was to make 

 them penetrate its tissue most intimately. Maceration, M. Bouche- 

 rie soon found, like his predecessors in the same path, to be insuf- 

 ficient, the substances in solution only penetrating a very little way. 

 He then tried various processes of injection ; but all inferior to that 

 imagined by M. Breant, and therefore less effectual. He then be- 

 thought him of effecting the needful penetration of the wood in the 

 green state, and before it had been sensibly altered by drying and 

 seasoning: he askcl himself if the force which determines the 

 ascent of the sap might not be taken advantage of after the tree was 

 cut down, as a means of determining the entrance of a sohition of 

 pyrolignite of iron ? And all his trials in this direction answered his 

 expectations fully. M. Jioucherie had, in fact, discovered a means 

 of securing the penetration of the minutest pores of the largest log 

 by a substance capable of rcnderinij it incorruptible. No one before 

 M. Boucherie thought of taking advantage ot an admitted physiolo- 

 gical fact for such a purpose. He announces the principle upon 

 which he proceeds in these terms: " If a tall tree be cut down at 

 the proper season, and the bottom of the trunk be then immersed in 

 a saline solution, weak or strong, the liquid is powerfully drawn up 

 into the tree, penetrates its most intimate tissui^s, rises to its small- 

 est branches, and even to its terminal leaves.''" 



In the month of September, a poplar, upwards of 90 feet high and 

 nearly 10 inches in diameter, was cut, and the bottom of its bole 

 plunged in a vessel containing a solution of pyrolignite of iron mark- 

 ing 8" of the areometer of Beaume : in the course of six days it had 

 absorbed upwards of 00 gallons of the fluid. 



In his flrst experiments, .M. Boucherie pn»curcd the nerdful 

 absorption by placing the bottoms of his trees in vessels containing 

 the solution ; but this mode of proceeding was obviously full of dif- 

 ficulties and open to many objections : the weight of a green tree ot 

 large size, with the whole of its top and branches, is often enormous, 

 and to raise a mass of the kind once down again into the perpen- 

 dicular was no easy task : it implied recurrence to certain mechani- 

 cal means which are not always at hand, and necessarily expensive. 

 M. Boucherie, therefore, tried other modes of making the trees 

 absorb ; he adapted a sac of impermealile material to the bottom of 

 tiie trunk laid on the ground, and irUo this sac he j^oured his solution, 

 and this method answered very well, llr n«^xt took advantage of 



' Ann. (If (hnnie, t. !\\i\. p. I.li. 



