1809. 
pose, though in this respect it is inferior 
to chat of cantharides, prepared by infu- 
ging two grains in one ounce of spirits, 
which has been found to be so effectual 
in the extirpation of bugs. Pierner_ as- 
serts, that a simple decoction of alves 
communicates a fine brown colour to 
wool. Fabroni,:of Florence, has ex- 
tracted a beautiful violet colour, which 
resists the acids and alkalis, from the juice 
of the fresh leaves of the aloe exposed.to 
the air by degrees. The liquid first becomes 
red, and at the end of a certain period 
turns to a beautiful purple violet, which 
adheres to siik by simple immersion, with 
out the aid of acids. 
Ricuarp WaLKER, esq. of Oxford, has 
proposed an alteration in the scale of the 
thermometer, which suggested itself to 
him during a long course of experiments, 
and which has been adopted byhimselfand 
his friends from the persuasion of its being 
founded on the truest principles. — The 
two fixed points, the freezing and boiling 
points of water as they have hitherto been, 
will (he observes) probably never fail to 
be continued, as being perfectly sufficient 
for the accurate adjustment of thermo- 
meters. The commencement of the 
scale, and the number of divisions only 
appear to claim attention. ‘With respect 
to the first, since neither the extremes of 
heat or cold are lik ely to be ascertained, 
the hope of fixing O ateither of these may 
be entirely relingui shed, and it remains 
to fix it at the fittest intermediate point. 
Here I propose the following mode of gra- 
duation, Having ascertained that the 
“temperature. of 62° of Fahrenheit is the 
temperature at which the human body in 
health is conscious of no inconvenience 
from heat or cold, and that a deviation 
fromthat pointof only one or two degrees, 
above or below, actually produces that 
effect under ordimarycircumstances, | fixed 
my zero or O there. I adopted the divi- 
ons of Fahrenheit, considering those: of 
Reaumur, the centigrades, &c. as too few, 
and decimaldivisions unnecessary. Hence 
it will follow that 0 being placed at 62° of 
Fahrenheit, 150° will be the boiling, and 
minus 30°, the freezing point of water; 
and all other points on Fahrenheit’s scale 
may be reduced to this, by subtracting 62 
for any degree above 0 of Fahrenheit, and 
adding, 62 for any degree below 0. For 
ordinary meteorological purposes, a scale 
of this kind extending to 65°, above, and 
as many below 0, will be sufficient.” 
Tt has been found that camphor mixed 
with different fixed oils and sand, in order 
to divide the particles, may be purifed of 
Literary and Philosophical Intelligence. 
283 
its oily particles, and deprived of its ers 
pyreumatic smeil, when sublimed with a 
smal] quantity of potash. The process 
by which this. effect is produced, is de. 
scribed as follows: two drachms of cam 
phor, with considerable See a tak ail 
smell, and 2s, were mixed with one of 
olive ‘oil, and eight Of Saud; after which 
twenty grains. of pure potash were-added 
and heat applied; but though it was 
greater than is necessary for its sublima- 
tion, the product was perfectly frée from 
empyreumatic smell, and a little whiter 
that it generally is PE substitution of 
linseed oi] produced no alteration in the 
product. Vhe stibearbonate does not 
answer the purpose, because in that state 
the affinity of potash for oils : less than 
when entirely deprived of cart bonic acid, 
FRANCE. 
The existence of gold-mines in France, 
was long questioned, even in that country, 
but it is now well known, that what was 
formerly the province.of Dauphiné, pose 
sesses several of that description. These 
mines are of two different kinds, some 
affurding native gold, others containing 
this metal mixed, or so intimately com- 
bined with diflerent metallic sutstances, 
that its presence is to be detected only 
bythe assay. ‘The native gdld-mines in 
the above-mentioned province are: that 
of la Gardette, that of Dorniliouse, or fa 
Freissiniere ; those of Orel, and the aus 
riferous ‘sands’ of the Rhone. Dormi- 
louse 15 situated in the present Paes 
ment of the Upper Alps, and Orel in the 
department of the Dréme. The moun- 
tain of Gardette rises above the village 
of the same name, four miles south of the 
town of Oisans. Its mine was included 
in the circle of mines, grantéd to Stanis- 
lans, Count of Provence, brother of Lovis 
XVI. by a decree of the council of state. 
Fhis mountain, which is 1410 yards 
above the sea, has at its foot a perpens 
dicular chit, above 220 yards in height. 
ts base is a reddish granite, composed of 
red feltspar, green steatitic quartz, and 
erey mica. - Above this is a laminar 
quartz rock, of a. blackish grey. This 
micaceous rock, im which the vold ds 
found, is covered by a secondary lime- 
stone, which forms the whole of the ep~ 
per part of the mountain. This is of a 
deep blue grey, and contains belemnites 
and ammonites, The inclination and 
direction of its strata, vary greatly; but 
in general they incline to the north, at a 
greater or less angle, which appears to be 
determined by the slope of the primitive 
rr dck, 
