652 
hours in the furnace, heated up to the tem- 
purature required for baking bread, is suffi- 
cient: if thicker, it is left in for a propor- 
tionably longer time, at the end of which it 
is withdrawn with caution, and cooled, after 
which it is put for thirty seconds into river 
water, withdrawn for a few seconds, and 
then, again, immersed for a minute or two, 
according to its thickness. The piece is 
then exposed to the air, and, at the end of 
three or four days, has acquired the hard- 
ness and density of marble. It may then 
be polished. 
To Destroy Flies.—During the course 
of the last summer, numerous accidents to 
children were recorded, in consequence of a 
deleterious composition, generally king’s 
yellow, a preparation of arsenic, being em- 
ployed for the destruction of flies; this ob- 
ject may be accomplished very safely, and 
completely, by a strong infusion of quassia 
wood sweetened with sugar. 
Encke’s Comet.—On the second or third 
of the last month (November), Encke’s 
comet, the original discovery of which we 
owe to the sister of the late Sir William 
Herschel, and the return of which has been 
recently expected by astronomers with much 
anxiety, was found -by Mr. South, in that 
part of the heavens exactly; which theory 
had assigned as its place at the time. As 
this nebulous body is much too small te be 
visible in any ordinary telescopes, we only 
notice its return as indicating, in an exten- 
sive degree, the perfection to which the 
science of astronomy is brought. 
Fall of an Aerolite.—The following ac- 
count of -an aerolite, weighing thirty-six 
pounds, which fell at 11, A.M., September 
14, 1825, at Vaigou, one of the Sandwich 
Islands, is given by a lieutenant of Captain 
Kotzebue, in his voyage round the world. 
A short time previous to its fall, the sky 
became charged with clouds, until the 
whole island was covered with a dense 
black veil. The fall of the stone was imme- 
diately preceded by a violent gust of wind 
from the N. W., and, even at sea, sounds 
like those of thunder were heard. Imme- 
diately after these detonations, the aerolite 
fell in the middle of the village of Gana- 
gauro, and broke into pieces on touching 
the ground. The Russian travellers gathered 
many of these pieces, one weighing fifteen 
pounds. They resemble the aerolites gene- 
rally known. 
German Method of Expediting Vege- 
tation.—A branch, proportioned’to the size 
of the object required, is sawn off the tree, 
the flowers of which are to be produced, and 
is plunged into a spring, if one can be 
found, where it is left for an hour or two, 
to give time for such ice as may adhere to 
the bulb to melt, and to soften the buds; 
it is then carried into a chamber, heated by 
a stove, and placed in a wooden vessel, 
containing water; quick lime is to be 
added to the water, and left for twelve hours. 
The branch is then to be removed into 
Varielies. 
-tions where the radiation of caloric goes on 
(Dec. 
another vessel, containing fresh water, with 
a small quantity of vitriol to prevent its 
becoming putrid. In a few hours the flow- 
ers will begin to appear, and, afterwards, 
the leaves; if more quick-lime be used, 
the flowers will appear quicker; if, on the 
contrary, none be used, the branch will 
vegetate more slowly, and the leaves will 
precede the flowers. 
Observations on Amber.—It is well 
known that amber is most commonly found 
in brown coal, and that it has been observed 
in the trunk of a tree, lying in a mass of 
brown coal. There is no doubt whatever of 
this fossil resin having been originally a 
vegetable product. The numerous bodies 
found inclosed in it, as, for example, spi- 
ders, wings of all sorts of insects, a corolla, 
perfectly blown, impressions of bushes and 
branches, which are not uncommon, suffi- 
ciently prove that amber, like common 
resin, originally flowed in the state of a 
balsam; and that it afterwards hardened 
into the form of a resin ; which, on ana- 
lyzing, is found to contain, at least, five 
different substances:—1l. An odoriferous 
oil in small quantity :—2. A yellow resin, 
intimately combined with this oil, and 
which readily dissolves in alcohol, ether, 
and the alkalis, which is very fusible, and 
resembles common resins not of fossil origin : 
3. A resin, difficultly soluble in cold alcohol, 
better in boiling alcohol, from which it 
separates, on cooling, in the form of a white " 
powder, and which dissolves in ether and 
the alkalis. These two resins, and the 
volatile oil which ether extracts from am- 
ber, form, after the evaporation of the ether 
upon water, a natural viscous balsam, of a 
strong smell, and a bright yellow colour, 
which, subsequently, hardens, preserving a | 
portion of its odour. There is every reason a 
to suppose that this body is precisely what 
amber originally was, but still, perhaps, less 
rich in essential oil than then, and that the 
insoluble parts of amber have been formed, — 
by time, from the alteration of this balsam, 
a portion of which has been enveloped, and 
defended from further alteration. The 
fourth substance contained in amber, is 
succinic acid, which is dissolved with the 
balsam by ether. The fifth substance is 
insoluble in alcohol, ether, and the alkalis, 
and bears some relation to the matter which 
has been found in gum lac, and which has 
been designated as the principal of lac; this is 
found in the greatest quantity when this 
resin is dissolved by an alkali, and bleached 
by chlorine and precipitated. 
Influence of Radiation on Malaria.— 
A theory of very considerable importance 
has recently been laid before the public, by 
Mr. Addison, the ingenious author of a dis- 
sertation on the Malvern Water, that the 
radiation of caloric from the earth has great 
influence in determining the site of malaria. 
The following is a brief summary of his 
views on the subject: viz. all those situa- 
oer? @ 
