488 
ebjects, as fith, which huis with fpon- 
taneous light in a latent ftate, do not 
emit it, when deprived of life, but from 
fuch parts as have been fome time in.con- 
tact with the air, and that a blaft from 
bellows does not increafe this fpecies of, 
Tight, as it does that which proceeds from 
combuftion: from a /fecond feries it ap- 
pears, that oxygen gas does not aét upon 
this light, fo as to render it more vivid 
than it is in atmofpherical air: from the 
zhird feries, it is deferving of remark, that 
azotic gas is favourable to the fponta- 
meous light emitted from fithes, but ex- 
tinguifhes that proceeding from rotten 
wood: from the fourth and fith it appears, 
that hydrogen and carbonic acid gaffes 
prevent the emiffion of fpontaneous light, 
and. extinguifh it when emitted: _ the 
~ New Patents lately enrolled, 
[June i, 
next three feries of experiments. thew, that 
fulphurated hydrogen gas extinguifhes — 
fpontaneous light fooner than carbonic 
acid gas: that nitrous gas prevents the 
emifion of light, and extinguifhes that 
which is emitted, and that it is completely 
extinguithed in a vacuum. From fome 
other experiments it appears, that folar 
light, when imbibed by Canton’s phof- 
phorus, is fubjeét to the fame laws, with 
refpect to heat and cold, ag the fponta- 
neous light of fithes, rotten wood, and- 
glow-worms. 
*,* In this Department of our Mi ifeel- 
Lemp: will hereafter be given an account of 
all the principal and important difcoveries 
and facis recorded in the Tranfactions of the 
various Literary and Philofophical Societies 
in Great Britain, 
NEW.PATENTS LATELY. ENROLLED. 
m 
M. PAUL DE PHILIPSTHAL’S PATENT 
(of .the LYCEUM, STRAND,) for the 
INVENTION. of reprefenting 11 @ DARK 
SCENE, HUMAN FIGURES, i Various 
CHARACTERS; SIZES, Ge. Ge. 
HE Patentee profefies to have dif- 
covered, by indefatigable refearch 
and numerous optical experiments, a new 
method. of producing yeprefentations of 
apparitions and fpeétres. ‘The apparatus 
canfilts principally of two concave glaffes 
or metal reflecters, fecured in a dark 
clofet, before which an artificial light, 
protineabh to. their foci, is applied, 
d direfted upon a piciure reprefenting 
the appari ition. Lenfes are made.ule of 
to throw the image of the picture on a 
tranfparent fcreen, which is hung pee 
the darkened clofet, or lanthorn, and th 
fpeGator. Whenthe mirrors wibisiene 
nearer the {creen, the objeét is diminifhed 
in fize, and appears, according to the 
laws of perfpe&tive, to retire, and when 
taken farther off, the fize of the objeét is 
enlarged, while it appears to appreach the 
fpeftator. M. Philipfthal pas, in his 
f{pecification, given particular inftructions 
for producing the yarious optical decep- 
— which he has, for fome time pait, 
ccefsfully exhibited atthe Lyceum to 
pag audiences, and at the fame time 
claiming, in high terms, the ‘* protection 
of his Britannic Majefty to his meritorious 
difeoveries.”” 
Obfervationn—Every perfon conver- 
“making will admit of. 
fant in the very firft elements — of {cience 
will eafily perceive, that thefe meritorious 
difcoveries, as they are called, depend upon 
the fimple and well- known principle of 
the magic lanthorn—and the various inva- 
fions made upon this patent, under the 
names of Skiagraphema, &c. &c. are 
pretty cogent proofs, that the invention 
had no claims to that fort of novelty which 
gives exclufive privileges. Indeed, we 
iknow that the Phantafmagoria had been 
exhibited at.a much earlier period at Paris 
than at London, by M. Robertfon, to 
whom we apprehend M, Philipfthal is in- 
debted for the invention. The Parifian 
exhibition was intended avowedly for the 
very ufeful purpofe of diffipating all vul- 
gar notions, prejudices and fears, re{pec- 
ting ghofts and apparitions. But at the 
Lyceum no attempt has been made to ex- 
plain, to thelefs enlightened part. of the 
audience, the principles upon which the 
delufions are founded, or the apparatus 
with which the exhibitions are made. » 
—— \ 
MR. DONALDSON’S PATENT (BRISTOL) 
for a METHOD of making all KINDs of. 
GLASS in a more EXPEDITIOUS MAN=— 
NER than kitherto attempted 
Mr. Donaldfon propofes no alteration 
in}the materials for making glafs, nor inthe 
proportions ufually adopted. The princi- 
ple of his invention confifts in the applica. 
tion of a ftronger heat, at a much lefs ex- , 
pence, than the common operations of glafs- 
And, although 
he 
