446 
ment is introduced into this hole, leaving 
the index endexposed to view below the 
door of the oven; the channel may, how- 
ever, be made in any other convenient 
part of the oven. 
=i 
MR. MAYER OPPENHEIM’S, (LONDON,) for 
a Red Transparent Glass. ° ‘ 
The nature of this invention may be 
thus described: We are directed to take 
of the materials that compound the flint-- 
glass, to purify them, and to add to them 
an equal quantity of brann-stein, or 
braun-stein, a species, we presume, of 
manganese ore ; mix them well together, 
and place them in a reverberatory fur- 
nace for thirty-six hours, when the calci- 
nation will be completed. This calcina- 
tion must be cohobated, or repeatedly 
exposed to the action of warm water, till 
no saline particles remain, when it may 
be dried. and an equal quantity of sal- 
ammoniac put to it; and it is then to be 
Jevigated, or reduced to powder, by the 
help of distilled vinegar. It is now to be 
Literary and Philosophical Intélligence; 
[Dec. I, 
dried and put into a retort, well secured, 
placed in a sand furnace, and exposed, 
eighteen hours to a fire sufficiently strong 
for sublimation ; after this, the calx is to 
be separated from the sublimed matter. 
To this sublimate, an equal quantity of 
sal-ammoniac is to be added, and again 
Jevigated in the same manner as before 
directed. The mixture is to he brought 
back into the retort, and a fire applied. 
that shall be strong enough to convert. 
the braun-stein to a liquid. Of this: 
liquid, half an ounce is to be taken, and. 
to this thirty grains of dissolved Dutch 
gold are to be added. This quantity is 
to be mixed with every pound of the 
flint materials, and the mixture being 
placed in a reverberatory furnace, there 
will be produced a white flint glass, 
which, on a second exposure to the same. 
heat, will be red and transparent, 
The above-named compounds of the: 
fiint-glass, contain two parts of lead, one 
part of sand, and one part of saltpetrg 
or borax. a ' 
VARIETIES, Literary ann PurLosoPpHIcalL. 
Including Notices of Works in Hand, Domestic and Foreign. 
oJ 
& * 
Authentic Communications for this Article will always be thankfully received. 
R. Drake will shortly publish, in 
four vols. 8vo. under the title of 
the Gleaner, a selection of the best 
essays from those periodical papers 
which have not been included in the last 
edition of the British Essayists. It will 
be elegantly printed on demy, and on 
royal paper, to match with the recent 
&vo. editions of the Tatler, Spectator, and 
Guardian; and will afterwards be re- 
printed aniform with the British Essayists. 
A Life of the late Arthur Murphy, esq. 
by Jesse Foot, esq. his executor, is in 
the press. It will form a quarto vo- 
lume, and contain the Epistolary Corre- 
spondence of Mr. Murphy with many 
distinguished persons, during a period of 
more than fifty years, 
An Account of the Isle of Man, com- 
prising its history, antiquities, and pre- 
sent state, fromthe pen of Mr. Georce 
Woops, will be ready for publication in a 
few weeks. | 
The History of Lynn, civil, commercial, 
iographical, political, and military, from 
the earliest accounts to the present time, 
by Witrram RicHarps, A. M. will 
shortly be completed in one large 8vo. 
volume. Coes 5 
_.Mr. Marrar’s work on Mechanics, 
will make its appearance in the cours@ 
of the present month. ; 
Mr. Curtry, of the Middle Temple, 
has announced hisintention of delivering, 
immediately after Michaelmas Term, 
a practical course of Lectures on Com- 
mercial Law. ‘This series will compre 
hend dissertations from the best writers 
on the Lex Mereatoria among nations, 
as acknowledged by our manicipal law ; 
on the commercial privileges and dis- 
abilities of aliens; on the modes adopted 
by the different branches of the British 
legislature for the promotion and regu. 
lation of foreign and domestic commerce; 
and on the spirit and effect of all the 
various mercantile contracts. The ob- 
ject of these lectures is not only to assist, 
by their practical utility, the different 
members of the legal profession, but also 
to arrange these extensive and important 
branches of the British Constitution in a 
clear and comprehensive point of view, 
for the information of those gentlemen: 
who may be preparing to embark either 
in commercial pursuits, or in the public 
service of their country. The lectures 
will be delivered twice a week, in the 
evenings of Monday and Thursday, in 
Gincoln’s Inn Hall, which the Honourable 
. Society 
