General JVotices. 151 



stances, the authoi* has recourse to no complicated or expensive me- 

 chanical means: he takes advantage of all the absorbing force, (force 

 apiratrice,) of the vegetable itself, and that is sufficient to transport 

 from the base of the trunk to the leaves, all the liquids that are in- 

 tended to be introduced, provided they are kept within certain limits 

 of concentration. Thus, if a tree in full sap js cut at the base, and 

 plunged in a tub containing the liquor it is meant to absorb, it will 

 ascend, in a few days, to the highest leaves, and all the vegetable 

 tissue will be imbued, except the heart of the tree, which, from its 

 hard nature, particularly in old stems, always resists penetration. It 

 is not even necessary that a tree should have its branches and all its 

 leaves; a few reserved at the top are sufficient for the purpose. 



It is not necessary to have the tree standing, which would often 

 render the operation impracticable: it may be cut down, and after 

 having all the useless branches lopjjcd oft", and its base then put in 

 contact with the liquid to be absorbed, which penetrates, as usual, 

 into all its parts. Indeed, it is not ever necessary to cut down the 

 tree; for a cavity made in the trunk, or the greater part of the sur- 

 face dented with a saw, is sufficient, by putting those parts in contact 

 with the liquid, to cause a rapid and complete absorption of it. 



If M. Boucherie has resolved the grand problem he proposed, in a 

 simple and practical manner, he has shown no less sagacity in the 

 choice of the substances he has adoi)ted to answer the purposes 

 mentioned above. When the durability and hardness of wood are 

 to be increased, and dry rot or moist decay avoided, he introduces 

 into the tissue pyrolignite of rough iron, (fer brut.) This substance 

 is well chosen, for crude (brut) pyroligneous acid is produced in all 

 forests, by the making of charcoal; it is easy to transform this into 

 pyrolignite of iron, by putting it in contact, when cold, even with old 

 iron, and the liquid thus prepared contains much kreosote, a sub- 

 stance which, independent of the salt of iron itself, has the property 

 of hardening wood and of preventing rottenness, as well as the rav- 

 ages of insects, in timber used for building. Authenticated experi- 

 ments, made in the cellars of Bordeaux, on hoops prepared by the 

 author, have yielded the most irrefragible proofs of the great dura- 

 bility of the wood prepared by his plan. Ordinary hoops were re- 

 duced to powder at the least effort, while his were as solid as at the 

 first. 



When the warping of timber, (jeu des bois,) preserving its elas- 

 ticity, and rendering it less combustible, are considered, the author 

 finds a cheap preservative in the use of earthy chlorides, (chlorures 

 terreux.) Impressed with the idea that his plans are soon to come 

 into universal operation, he has not been satisfied with merely using 

 chlorine of calcium, (chlorure de calcium,) which costs so little, but 

 has tried the efficacious water of the salt marshes, which costs no- 

 thing, and found it to contain all the requisite qualities. Timber 

 prepared by these saline solutions preserves its flexibility after seve- 

 ral years' exposure to the air: when cut into thin slices, (feuilles,) 

 they may be twisted spirally, and retwisted in a contrary direction, 

 without cracking. When exposed to the air, it never either warps 

 or splits, however dry it may be: and it does not burn, or, at least, 

 with so much difficulty, that it is incapable of extending the ravages 

 of a fire. 



