VALUE OF CORROSIVE SUBLIMATE IN PRESERVING TIMBER. 359 
corresponds with the natural phenomena 
that comes under our immediate observa- 
tion; w'herever we see oigani7,ed life, we 
see that it has a birth, that it comes to maturi- 
ty, and gradually decays; wherever we see 
itmtion, we see that it exhausts itself in a ratio 
corresponding with its intensity ; and theie- 
foie, leasoning from analogy, we are justified 
in the inference, that the same rule and order 
may hold also in the heavenly bodies. 
8. Thatthemoon is gradually approximating 
towards the earth is an obvious corollary of 
the foregoing theory ; and here we shall be 
enabled to draw our inferences from two 
sources, astronomy and geology ; and, conse- 
quently, in the latter, from matters that come 
more immediately under our observation, for 
we hold, that at one time the earth occupied 
the places now occupied by Georgiura Sidus, 
Saturn, andJupiter, each respectively in the 
order of their succession , that at that period 
of her existence she was of much larger dia- 
meter than at this present time, and was 
probably attended by three, four, or more 
moons', the wrecks of all of which, save one, 
are now scattered upon the surface of the 
earth— and in these wiecks we expect to find 
further evidence of the truth of our theory. 
{To be contmued.) 
The Minister for the Marine and Colonies 
of France applied a short time ago to the 
Royal Academy for their opinion respecting 
the efficacy of a solution of corrosive sub- 
limate as a preservative of the timber, sails, 
and cordage of ships. A commission of five 
members was appointed to make the requisite 
inquiries, and to draw up a report of their 
proceedings. The report commences with a 
rapid survey of the various means which 
had been proposed and tried previous to the 
introduction of the corrosive sublimate. 
Among the numerous preservatives at differ- 
ent times recommended, we may enumerate 
various resins, animal, vegetable, and mine- 
ral oils, the muriate of soda, the nitrate of 
potass, quick-lime, baryta, the species 
of pyrites (?), which the English call 
mundic,” and which is partly composed 
of arsenic. This latter substance mixed 
with water was used to wash the tim- 
bers of the Queen Charlotte with ; but 
the shipwrights employed in the work suffer- 
ed severely from swellings of the glands, 
and two of them died in consequence. A 
practice which has been for a great length 
of time in use in many arsenals is to keep 
all their store or reserve timber floating in 
or sunk under sea-water : but this method 
too has its disadvantages ; for the wood 
thereby loses its proper density and strength, 
and it cannot, but with difficulty, be after- 
wards ever thoroughly dried. The saline 
matter, with which it has become impregnat- 
ed, is apt to dissolve whenever the atmos- 
phere is damp ; and thus a vessel built of 
such timber is inevitably rendered uncom- 
fortable and even unhealthy. The oxidation 
too of the iron and copper work is greatly 
accelerated by the presence of the muriate of 
soda. Lastly, it may be stated that the wood 
thus seasoned is by no means exempt from 
the very evil which the remedy has been 
used to counteract. In order that timber 
may remain sound for a length of time, it 
is necessary that it be thoroughly dried. 
The drying of timber is usually effected by 
exposing it for a length of time (under shel- 
ter if possible) to the air. But this being a 
tedious process, (three years may be stated 
as the average time required,) recourse has 
been had to artificial wai’mth. A too high 
degree of heat weakens the ligneous fibre, 
and by dissipating all its humidity — a certain 
degree of which is necessary to its sup- 
pleness and strength — renders it friable and 
disposed to split. It has been recommen- 
ded to dry and to preserve timber in beds of 
dried sand ; but this plan is evidently in- 
applicable for large quantities of wood. 
The process of that , disorganization of 
w^ood, so well known by the name of the 
dry-rot, has been repeatedly examined. The 
following appear to be the progressive steps 
of this destructive change. The wood being 
more or less humid, whether from retaining 
part of its natural humidity, or, in con- 
sequence of the long immersion to which it 
was during its seasoning subjected, commen- 
ces to undergo a sort of heating or fermen- 
tation, the result of some internal molecular 
movement, analogous to that which takes 
place during the decomposition of animal 
matters. By this fermentation and dissolu- 
tion of the juices of the wood, the reticular 
ligneous tissue gradually softens and cracks ; 
and in the cracks or fissures thus formed 
various cryptogamic plants begin to vegetate. 
The vegetations, which are in truth not the 
primary causes of the mischief, hut are 
rather the result of the preceding changes, 
multiply and increase in every direction, 
breaking up and disorganizing the ligneous 
tissue. This development of regular organi- 
zed vegetable productions succeeding to a 
previous decay of the wood, may be aptly 
compared to the generation of worms in 
putrefying aminal matter. 
Such appears to be the process of what has 
been called the dry-rot, or caries of wood ; 
a morbid action which commences with a sort 
of intestine fermentation or decomposition 
of the ligneous fibre, and terminates by the 
production of various cryptogamic plants in 
its tissue. It had been long well known that 
the corrosive sublimate of mercury has a 
powerful effect in arresting the putrid fer- 
mentation and decomposition of animal mat- 
ters. It had been used in preserving anti- 
monial preparations, objects of natural histo- 
ry, in embalming, &c. The most putrescent 
structures, such as the nervous pulp, acquires 
a firmness from the sublimate, which enables 
it to resist decay. Botanists, too, had fre- 
quently employed it in the preservation of 
their herbaria. So far back as the year 1815, 
ON THE PRESERVATION OF TIMBER 
FROM THE DRY ROT BY THE COR- 
ROSIVE SUBLIMATE OF MERCURY. 
