Page:Popular Science Monthly Volume 5.djvu/240

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228
THE POPULAR SCIENCE MONTHLY.

ble substances, and disperse themselves through the air, and fall to the soil for its enrichment.

The pith of the whole matter is this: Cannot the dead body be, by some chemical process, metamorphosed into stone, and then reduced to powder, for preservation, like ashes, in the funeral-urn, or scattered to the winds of heaven, to seek its normal starting-point for future transitions?

 
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A NEW PROCESS FOR THE PRESERVATION OF WOOD.
By M. A. HATZFELD.

THE question of the preservation of wood, applied to the sleepers of railroads, telegraph-poles, and wood for mechanical purposes, etc., becomes from day to day more urgent, in presence of the increase of railways. Of all the materials employed until now, there remain hardly two in use—sulphate of copper and creosote.

The sulphate of copper gives only imperfect and very variable results. This we can easily understand: this very soluble salt must be in part diluted by rain-water and the humidity of the soil, so that, at the end of a certain time, the preservative effect has disappeared. Besides, this process very often causes alteration in the wood from the impurity of the salt employed, or from its acid reaction—circumstances which it is very difficult to avoid, when we operate on a large scale with materials containing, in a state of combination, an energetic acid, having for its base a metalloid, such as chlorine, sulphur, nitrogen, etc.

As to creosote, it is a substance comparatively rare, of a high price, of an inflammable nature, and, in consequence, difficult to transport and handle. Besides, and this perhaps is the most important consideration, it is a product which, like those we extract from fossil-coal, may, some day or other, in consequence of a discovery analogous to that of aniline, acquire a high industrial value. Its employment would then become impossible for the preservation of wood.

Hence we may say that these two substances do but imperfectly comply with the necessary conditions, and the question arises, whether there is no other material that might be used in all our present yards, i e,, that might be injected equally well by Boucherie's process (gravitative force of a heavy column of liquid), and by the modified process of Bréant (successive action, in a close tank, of a vacuum and of a pressure of several atmospheres). I propose the acid tannate of protoxide of iron, and base my views on the following considerations:

Wood, as we know, consists of cellulose, or cells in which there is