1807.] 
from optical illutions. To a perfon ftand- 
ing betore this machine, a door is appa- 
rently opened, and a phantom makes its 
appearance, coming towards him, and in- 
creafiag in magnitude as it approaches. 
This phantom appears in the air lke a 
beautiful painting, and in fuch brilliancy 
of colourmg that it is not neceflary to 
make the room dark; this picture appears 
to the greateit advantage when it is il- 
luminated. Mr. W. has applied his ma- 
chine to reprefent the phafes of the 
-tnoon, the primary planets, and other 
phenomena in the heavens. 
Mr. Cornnettus Varvey has laid be- 
fore the public fome remarks on atmo- 
fpherical phenomena, particularly on the 
formation of clouds; their permanence ; 
their precipitation in rain, fnow, and 
hail; and the confequent rife of the ba- 
rometer. ‘The inferences drawn by this 
gentleman are, 1. That no cloud can be 
formed, or exift, without eleétricity. 2. 
That no cloud can fall in rain till it parts 
with fome of its ele¢tricity. 3. That in 
fine weather the earth muft be giving 
electricity to the atmofphere by means of 
vapour, and in ftormy weather the at- 
mofphere mutt be giving eleétricity to the 
earth by meaus of vapour, rain, or light- 
ning. 4. That in fine weather the clouds 
are feparating, and in ftormy weather 
uniting. 5. That electricity is the fuf- 
pending power in clouds. 6. That dry 
air is a conductor of heat, but a non-con- 
ductor of electricity. 7. That water can 
exift permanently in four ftates, and tem- 
porarily in one only. Two of thefe are 
effected by electricity, and three without 
it, The firft ele¢trical ftate is that of 
cloud, which is fo much charged as to be- 
come lighter than air at the furface of 
the earth; the fecond is a complete fatu- 
ration of water with the electric fluid, 
which produces a tranfparent and elattic 
fluid light cnough to float above the 
higheft clouds. The firft of the three 
other ftates is ice; the fecond is liquid; 
the third, which is quite temporary, is 
vapour; for, as foon as the fupply of heat 
by which it is raifed from the earth is 
withdrawn, it condenfes, and returns 
again to the ftate of water. A confe- 
quence of this theory is, that when a 
cloud lofes its eleétricity in an atmo- 
fpheré below the freezing point, then fnow 
is prodyced, for the vapours will be 
frozen in the aét of uniting: and parti- 
cles of moifture united into rain, and 
patling through a cold region in thew de- 
Literary and Phailofophical Intelligence. 
375 
{cent to the earth, will come down in the 
form of hail, ) 
Dr. Cranny,of Durham, has juft pub- 
lifhed an Maitory and Analyfis of the Mines 
ral Waters at Butterby, near that city. 
Ruffia, 
The mineral waters of Lipetzk, in the 
province of Tambow, in Ruffia, have 
lately been analyfed by M. Skell, and 
are found to contain in one pound as fole 
lows: 
Carbonat of iron - 
22 grains 
oflime - #5 
Muriate of magnefia - ~ 3% 
of soda - 25 
Sulphate of lime - & 
——— of foda > £ nearly 
Bitumen - - és 
From this analyfis, and other accurate 
obfervations, it thould feem that the wa- 
ter of Lipetzk has fome analogy to that of 
Pyrmont: it has, however, lefS of the irs 
ritating quality, with regard to, the car- 
bonic; lefs uf the power of folution with 
re{pect ta falts, and more of the tonic pow- 
ers of iron. On thefe accounts M. S. af- 
ferts that the water of Lipetzk ftimulates, 
gives vigour, increafes the elafticity of the 
mufcular fibres and the activity of the or- 
gans, enriches the blood, and imparts 
more colour to it; while on the other 
hand it liquefies tenacious, flimy, and 
condenfed fiuids, removes obttructions in 
the canals, qualifies the fharpnefs of hue 
mours, and deftroys worms. 
France. 
The public will foon be prefented with 
the Narrative of the Voyage of Difcovery 
in the South Seas, performed during the 
years 1600, 1801, 1802, 1803, and 1804. 
It will comprehend the hiftorical part; 
the manners and defcription of the peo- 
ple ; and the department of natural phi+ 
lofophy and meteorology, forming toges 
ther four quarto volumes! It will be 
drawn up by Mefirs. Peron and Le- 
suEUR, and will be printed at the expence 
of the government. The part containing 
the natural hiftory will be publithed by 
fubfeription, i 
M,Tenon haslately prefented to the Na- 
tional Inftitute a defcription of the teeth of 
the cahalot and crocodile. The teeth of 
the former have no enamel, but ouly the of 
feous cortex. The one, we are informed, 
may be ealily diftinguithed from the other, 
becaufe the enamel is much harder, and 
is entirely diffolved in the acids, without 
leaving any gelatinous parenchyme. The 
tufks of the elephant, and the grind- 
Bs ers 
