S& 
after being wafhed, be thrown into nitrous 
acid, an entire folution takes place, ac- 
companied by a fireng effervefcence; hence,, 
he infers, that the precipitate was an arti- 
ficial combination of alumine and carbo- 
nic acid. GREN, onthe other hand, af- 
ferts,; that by a careful decompofition of 
a folution ef alum, a non-effervelcent pre- 
cipitatéis obtained ; and hence infers that 
alumine has no affinity for carbonic acid. 
Theie differences of opinion, and contra- 
dictory fa&s, Sauffure has harmonifed,. 
and by an excellent ieries of experiments 
has thrown much additional information 
on this interefting fubject. Having pre- 
pared an effervefcent alumine, by decom- 
pofing a folution of alum’ by carbonated 
ammonia, re-difiolving the precipitate in 
muriatic acid, and again precipitating it 
by carbonated ammonia, he divided it into 
two portions, the one finely pulverifed, and 
the other in lumps ; thefe were expofed to 
the open air for eighteen months, at the 
end of which perisd, it was found, that 
the pulverifed alumine was no longer effer- 
vefcent, but that the portion in mafs was 
confiderably fo. By digefting them in 
pure potafh, fome ammonia was difengaged 
from the effervefcent alumine, but not 
from the other; hence Sauflure infers, 
that the effervefcence was owing to carbo- 
nated ammonia which remained in the 
precipitate in mafs, but had evaporated 
from that which was pulverifed. Toa 
folution of aium, a little carbonated potath 
was added, but not foas to decompofe the 
whole of it: the precipitate hence refult- 
ing was a pure non-eftervefcent alumine ; 
the effervefcence,therefore, of common pre- 
cipitated alumine, as in Fourcroy’s expe- 
riment, was owing to its retaining fome 
carbonated potafh. A completely neutra-_ 
lized nitrat of alumine was prepared, to 
which was added 2 fmall piece of ¢alca- 
reous fpar; a decompolition took’ place, 
accompanied by the extrication of carbonic 
_acid, and the precipitate was pure non- 
effervefcent alumine.. Some pure: non~_ 
effervefcent alumine was diffufed in water, 
which was afterwards impregnated with 
carbonic acid: tle clear filtered liquor, 
upon expelure tothe air, gave out its car- 
bonic acid, and a few grains of pure non-- 
efferveicent alumine were depofited. An 
immediate turbidnefs and precipitate was 
allo cccafioned in another portion of the lt-. 
gquor, by a few. drops of pure ammonia. 
‘The pure cryftallited clay cf Haile, in 
Saxony, which is generally reckoned a na- 
tive carbonat of ajumine, diffolved in ful- 
phuric and nitric acid, without any effer- 
vefcente, Hence it follows, that the na. 
Literary and Philofophical Tatelligence. 
 [Aug. 1, 
tive carbonats of alumine do not contain 
carbonic acid; that the artificial alumines 
owe their effervefcence to a portion of 
mild alkali fill remaining mixed with 
them; that alumine is combinable with 
carbonic acid. through the medium of 
water, but their. mutual affinities are fo 
flight, that the acid is feparated by the 
pure alkalies, and even by atmofpheric 
acid. 
From fome experiments of M. ACHARD, 
it appears, that the germination of feeds 
is confiderably haftened, by placing theny 
in acondented atmofphere, the quicknefs 
of their evolution, ceteris paribus, being ac- 
cording to the fpecific gravity of the at- 
moipheric air in which they are placed. 
Various {mail animals being placed in de- 
terminate quantities of comprefigd air, it 
was found that they lived longer in this 
than they would have done if the fame 
weight of airhad been only at the ordinary 
atmo/{pheric preflure ; thus the fame quan- 
tity of air that would fupport a bird for an 
hour, when .comprefied to a third of ‘its 
bulk, will fupport it foran hour and forty 
minutes. “iy 
HumsoLpt, who is at prefent engaged 
in a {cientific journey through the Spanifh 
South American dominions, has been mak- 
ing fome barometrical obfervations near 
the equator, from which it appears, that 
there are four regular atmolpheric tides — 
every twenty-four hours, feemingly de- 
pendent on the attraction of the fun, upon 
which winds and ftorms have no influence; 
the mercury falls from nine o’clock in the 
morning till four in the evening ; it rifes 
from four till eleven; it falls from eleven 
till half pait four in the morning, and re- 
afcends trom that time till nine o’cleck. 
A fimilar fa& had been previoufly obferv- 
ed at Bengal, where the barometer rifes 
and falls regularly every twenty-four 
hours... » Hi, alas 
Citizen MarGueEron, of the Military- 
hofpital at Strafburgh, has difcovered a - 
new fpecies of oil in the berries of the 
dogwood {(cornus fanguinea of Linnzus), 
Having procured ten kiiogrammes of the 
ripe berries, which, when in a fate of 
maturity, are of a blackith colour, they 
were laid in a heap to foften, and heat a 
little; being then wathed to a pulp, and 
. fubmitted, without further preparation, to 
the prefs, two litres of a fatevifcous oil 
were procured, of a clear green colour, 
without fmell, and without tafte. When 
mixed with fallad, it could not be diftin- 
guifhed from the beft clive oil; various 
methods were tried to free it from its’ 
green colour, but without fuccels 5 giek 
the 
& 
