| 
| 
454 
MR. WILLIAM HENRY CLAYFIELD’S 
(sRisToL) for a Method of reducing 
and extradiing LEAD and other ME- 
TaLs from a compound Subjtance, known 
by the Name of REGULUS, and at pre- 
ent obtained as the Refidue of certain 
ores .at the Lead-Furnaces, and aljo 
obtained in other Works or Mazufacéo- 
vies, which faid REGULUS appears to 
confift of the OXiDES of LEAD and 
ARSENIC, and alfo from ORES or NA- 
TIVE MINERALS, of nearly the fame 
Compofition. 
Inftead of the ordinary treatment” to 
which the ores of lead are commonly fub- 
jected, (that ts roafting at.a low red-heat, 
with or without the addition of caal,and 
lime, and fubfe vent fufion by a ftronger. 
heat, followed by drying up with lime 
and coal and a’ fucceeding fufion,) Mr. 
Clayfield adopts the following procefs :— 
Re firft by a ftrong heat fufes the regulus 
ina furnace, the bottom of which is co- 
vered with lime. To the fufed mafs is 
to be added a much larger proportion of 
coal and of lime, than is commonly uled 
in drying up or checking the fufion of 
lead ore. By this addition a confiderable 
quantity of the lead is feparated in the. 
metallic ftate, and runs to the bottom of 
the furnace, where it is to be immediately 
tapped out. More coal and lime are to 
Corre? Lift of New Publications. 
rine i. 
be added, and the whole mafs Is to be 
brought to the action of the flame, for 
fen or twelve hours, at the end of which 
period the mafs will be found ina ftate 
much lefs capable of fufion than before. 
The refidue is then expofed to a preater - 
heat, to extract the remainder of the lead 
and other metals, by the addition of com- 
buitible and other fubfances, according to 
the well-known practices of chemilts. 
Y 
Mr. James Waite has lately taken 
out a patent in Paris for a pendulum 
which defcribes an entirely new curve. 
The very remarkable flownefs of its mo- 
tion, renders this pendulum highly ufeful 
for aftronomical purpofes. In a future 
number we hope to be able to give a full 
defcription of this invention. 
NE . 
In America, alfo, Mr.Jaces ALRICHS, 
of the Delaware, has invented a new pen- 
dulum, conftructed with fix wheels and a 
pinion, inftead of twelve wheels and fix 
pinions, which were ufed in the moft fim- 
ple inffruments of this kind. “The in- 
ventor intends to fecure the benefit of his 
difcovery by a patent; and he afferts that 
pendulums may, by his plan, be made at 
Jefs expence, will need lefs repairs, and 
Jaft a mach longer time, than thofe of the 
former conftruétion. ™ 
LIST or rue NEW PUBLICATIONS in MAY. 
es 
xe As the List of New Publications, contained in the Monthly Magazine, is the 
ONLY COMPLETE EISZ’ PUBLISHED, and confequently the only one 
that can be ufeful to the Public for purpofes of general reference, it 1s requested 
that Authors and Publifbers ewill continue to communicate Notices of their Works, 
(polt paid), and they will always be faithfully inferted FREE of EXPENCE. 
CHEMISTRY. 
-Le€tures on the Elements of Chemiftry, 
delivered in the Univerfity of Edinburgh, by 
the late Jofeph Bleich, M.D. now publithed 
from his Manufcripts. By John Robinfon, 
L.L.D. 2 vols. gto. with plates, 31. 3s. boards. 
DRAMA. 
The Marriage Promife, as performed at the 
Theatre Royal, Drury-lane. By John Till 
Allingham, Efg. 2s. 6d, 
EDUCATION. 
"An Eafy Grammar of Geography, intended 
asa Companion and Introduction to the Geo- 
graphy for the Ufe of Schools, by the fame 
Author. By the Rev. J. Gold{mith. With 
maps. 12mo. 2s. 6d. Phillips, 
A Continuation of the New Guide to the 
Italian Language; or, Exercifes upon an en- 
tire new Plan. By G. A. Graglia. 12mo. 4s. 
A Mythological Dictionary, containing an 
Account of the Heathen Deities, é&c. adapted 
to the Ufe of Schools, 3s. beards. 
Elegantiz Latinz; or, Rules and Exercifes - 
iNuftrative of elegant Latin Style, intended 
for the Ufe of the higher Claffes of Grammar 
Schools. By the Rev. Edward Valpy. 3s. 
GEOGRAPHY. : 
The Gazetteer of Scotland, containing a 
Defcription of the Counties, Cities, &c. 
with.an Account of the Political Conftitu- 
tion, of the State of Agriculture, Population, 
Natural Hiftory, Seats of thé Nobility, &c. 
With a Map. 8vo. tos. 6d. boards. 
“" HISTORY. 
A Hiftory of the Wars which arofe out i ae 
the French Revolution, from their Com- 
mencement in 1792, until the Peace of 18026 
To which is‘ prefixed, a Review of the Caufes 
and early Progrefs of the French Revolution. — 
By Alexander Stephens, Efa. Two large ve- 
lumes, 
— 
