154 
‘day the thirty-first of December. The 
lectures will be given at nine o’clock im 
the morning, on Mondays, Wednesdays, 
and Fridays, at Dr. Reid’s house, Greu- 
ville.street, Brunswick-square, where 
further particulars may be known. 
~ Dr. Dennison and Dr. Byam Den- 
wison, will commence their course of 
Lectures on the Theory and Practice of 
“Midwifery, and the Diseases of Women 
and Children, at the London Hospital, 
on Monday, October 8th, at eleven 
o'clock. 
Dr. Buxton’s autumnal caurse of 
Lectures on the Practice of Medicine, 
will be commenced on Monday, the 1st- 
October. aa 
The winter course of Dr. Crarke’s 
and Mr. Crarke’s Lectures on Mid- 
wifery, and the Diseases of Women and 
Children, will commence on Friday, the 
‘5th October, at the house of Mr, Clarke, 
No. 10, Upper John-street, Golden- 
square. The Lectures are read every 
day from a quarter past ten o'clock in 
the morning wil a quarter past eleven, 
for the convenience of students attending 
the hospitals. The students will have 
labours when properly qualified. 
In pursuance of a petition to the 
House of Commons trom the trustees of 
the British Museum, Mr. Greviuxe’scol- 
“Yection of minerals has been valued by 
Drs. Babington atid Wollaston, and 
five. other gentlemen, who report that 
the whole collection consists of abuut 
20,000 specimens; that the series of 
crystallized rubellites, diamonds, and 
precious stones in general, as well as 
tbe series of the variaus ores, far Surpass . 
any that are known to them in the dif- 
ferent collections, and that the value of 
the: whole is 13,7271. including 
binets, which cost 16001. 
A canal has been projected from Bris- 
tol to join the Wiltshire and Berkshire 
canal, ator near Foxham. By this com- 
‘munication, and through the medium of 
the intended Western Junction and the 
Grand Junction Canals, a regular and 
safe navigation will be opened with the 
ports of London and Bristol, and all 
towns and_places contiguous to, or com= 
munieating, with them: 400,000]. has- 
teen subscribed to carry the plan into 
éxecution. 
A species of hemp, manufactured from 
the leaves of a_ particular kind of palm, 
which abounds in Sierra Leone and its 
neiczhbourhood, has recently been sent 
t» this country; and being made into 
eord, subjected to experiments calcu- 
Literary and Philosophical Intelligences 
the Cae 
(Sept. I, 
lated to ascertain its strength, as come 
pared with the same length and weight 
of commun hempen cord, the result was 
very satisfactory, it being found that 
hempen cord broke with a weight of 43ibs, 
three-fifths, white the African cord did 
net give way to less weight than S9lbs. 
two-tiths, making a difference in favour 
of the latter of 10ibs. in 43lbs. 
Captain Mansy, whose ingenious ine 
vention for preserving the crews, &c. of 
such vessels as inay be stranded on the 
coast, lately obtained parliamentary 
reward, has made some improvement 
on his invention, and exhibited them 
on the beech at Cromer; the ex. 
periments consisted in projecting the 
grapple, log-line, &c. from the mortar 
to the distance of 404 yards. 
Some notice has recently been taken 
of the art of printing from stone, known 
in Germany by the name of * chemical 
printing.” In the chemical printing’ of- 
fice at: Vienna, three different methods 
are empleyed; but that termed in relief 
is most trequently used. This is the ge- 
neral mode of printing music. The se- 
cond method is the sunk. This is pres 
ferred for prints. The third method is 
the flat, or neither raised nor sunk. 
This is useful fur imitating drawings, par-_ 
ticularly where the impression is intended 
to resemble crayons. For printing oF 
engraving in this method a bleck of mar- 
ble is employed, or any other caleareous 
stone, that is easily corroded, and will 
take a good polish. It should be twe 
inches or two inches and a half thick, and 
of a size proportioned to the purpose for 
which it is intended. A close texture is 
considered as advantageous. When the 
stone is well polished and dry, the first 
step is to trace the drawing, notes, or 
letters, to be printed, with a pencil. 
The design is not very conspicuous, but 
it is rendered so by passing over the 
strokes of the pencil a particular ink, of 
which a great secret is made. This ink 
is made of a solution of Jac in potash, 
which is coloured with the soot from 
burning wax. This appears to be the 
most suitable black fer the purpose. 
When the design has been gone over 
with this ink, itis left to dry, which coin- 
monly takes about two hours; but this 
depends much on the temperature and 
dryness of the air. After the ink is dry, 
nitric acid, more or less diluted, accord= 
ing to the degree of relief desired, ig 
poured on the stone, and corredes ~ . 
every part of it, except where defended 
by the resinaug ink, “Phe block being: 
, washed 
