PRESERVATION OF WOOD. 
TRANSLATED FOR THE SMITHSONIAN INSTITUTION BY C. A. ALEXANDER, FROM THE LEIPZIG “‘AUS DER ~ 
NATUR. U. S. W.” 
TE increased consumption of wood, more especially in the construction of 
railroads, has rendered the question of a future supply one of no little interest. 
Its importance, however, results not so much from the quantity employed in con- 
struction, great as that certainly is, as from the rapid decay of the sills of rail- 
roads and the consequent necessity of frequent renewal. A resort to the harder 
kinds of wood in place of the softer was an obvious and early expedient; but 
little is thereby gained, for the former also harbor within themselves the germ 
of destruction, and under the influences of the atmosphere pass speedily through 
the stages of decomposition. _ : 
Of course this process is more rapid in certain kinds of wood, and is the 
effect of a greater proportion of cellular tissue containing nitrogen. It is to 
this that wood, exposed alternately to moisture and dryness, owes its decay, 
because the proteine substances, as the nitrogenous combinations are called, pass 
into fermentation, develop carbonic acid, and thus produce the gradual decom- 
position of the mass, although the secoud chief constituent of wood, the so- 
called cellulose, is in itself unalterable, and resists all destructive influences. 
The more proteine, therefore, contained in the wood, the more easily and earlier 
does it undergo decomposition. 
Railroad sills of oak were found to last longer than those of softer wood, yet 
even these, though chosen with care, sufficed but for some ten years’ service, and 
then for the most part required to be renewed. But through the exclusive use of 
oak for this purpose, it was soon observed that the forests were becoming thinned 
beyond all hope of restoration, and that the price of this wood had advanced to 
a most inconvenient extent. These annually increasing disadvantages have had 
the effect of directing inquiry to the practicability of replacing, for many differ- 
ent purposes, the use of wood by that of other materials, chiefly stone and iron; 
but for the sills of railroads this substitution has not been found toanswer. Here, 
therefore, it was necessary to think of other means for prolonging the duration 
of wood, or at least for communicating to the soft woods, of which our forests 
are chiefly composed, a degree of durability which should qualify them to supply 
the place of the harder kinds. 
Plans for the conservation of wood are just as little as the wasting of the 
forests an incident of yesterday or to-day. As early as the reign of Charles 
II, of England, Lord Caernarvon had said, “ Wood is an outgrowth of the earth 
which nature provided for the payment of our debts,” and the first proposal for 
the preservation of wood by chemical means dates from that period. Of this 
the celebrated Dutch chemist, Glauber, was the author. ‘'T'wo other proposed 
methods date from the last century, and since the beginning of the present a 
great number have been brought forward. All those heretofore devised, and 
which have had in view chiefly the preservation of railroad sills, depend— 
1. On the abstraction of water from the wood before using it; 
2. On the elimination of the ingredients of the sap; 
3. On the chemical alteration of those ingredients; 
4. On the mineralization of the wood. 
Of the various proposals for this purpose we can here notice only those which 
