The Sun.
London, England, 1867-06-06 00:00:00

SCIE'NTIFIC JOTTINGS.

Among the photographic curiosities which are
daily springing up, we now have magical photo-
graphs—that is, such as can be made to appear and
disappear at pleasure. For this purpose they use
paper coated with gelatine, and they sensitize it in
a saturated solution of bichromate of potash. After
printing, the photograph is washed in order to dis-
solve the excess of gelatine. The effect is this :
When dry the photograph does not show the
slightest trace of an image, but if put into water
the latter will appear in a transparent state, to dis-
-appear again completely when dry. It may, how:
ever, be fixed by laying it carefully on a surface of
gum and water. Herschel's chrysotype, as is well
known, also produces such fugitive photographs by
another process. Mr. Leighton Pine is of opinion
that there is no need of seeking any new process for
obtaining fine proofs richly toned, since the ordinary
methods are quite sufficient for the purpose, pro-
vided the sensitive substances be properly dosed.
Thus, for instance, he thinks the following propor-
tions for salting paper the best : Water, 31 cubic
centimetres ; hydrochlorate of ammonia, 0,350 do. :
nitric acid, 0.130 do. ; and gelatine, 0.065 do. The
sensitizing bath consits of 2.6 gins. of nitrate of
silver for every 31 cub. centim. of water ; the paper
thus impregnated is exposed to the'emanations of
ammonia, and may then be printed as vigorously
as on albumenized paper. The toning is effected
with a salt of gold alkalized with chloride of
lime; after which the proofs are washed, and
fixed in a bath of 186 parts of water and 31 of
hyposulphytc.—M. Vivenot., jun., has found by
numerous experiments that, under the influence
of compressed air, having an increase of pres-
sure of three sevenths of an atmosphere, the pulse
falls at the rate of six strokes and a half per
minute ; but the phenomenon is only transitory,
and ceases soon after the excess of pressure has
been removed. The cause of this, according to
M. Vivenot, is purely mechanical, being due to
the increase of pressure at the surface of the
body, whereby the diameter of the smaller ves-
sels is narrowed, and capillary circulation ren-
dered more difficult. In making certain experi-
ments with glass for optical purposes, M.
Leroux was led to form a borate of magnesia
with an equivalent of calcined oxide of magnesium
and another of boric acid. This compound melts
at a strong white heat, and yields a very fluid liquid,
which, on being poured on a castiron plate, is trans-
formed into a slightly greenish sort of glass, remark-
able for its lightness and strength. But, strange to
say, if poured into platinum moulds, it will come
out quite opaque, partly of white marble. Hence
it appears that, to become glass, it must not be.
annealed.

SHIPPING INTELLIGENCE.

(By Electric Telegraph.)
GRAVESEND, Thursday Morning.

Arrived—Black Diamond and Fairy, both from Guern-
sey; Latone, from Madras; Jessie, from Guernsey; Trou-
badour, steamer, from Rotterdam; Baron Osy, steamer,
from Antwerp; Concordia, steamer, from Boulogne.
Sailed—Esther, steamer, for Paris; Panther, steamer,
for Boulogne.

DEAL, Thursday Morning.

Passed, June s—Blackwood, from Algoa Bay, for Lon-
don ; London, screw steamer, for Lisbon ; Chiltern, screw
steamer, for Trinity Bay—both from London.

MR. CIIARLES DICKENS.—At the Railway Bene-
volent Institution last evening Mr. Charles Dickens
repeated an anecdote that had been once told him by an
American sea captain. On a certain voyage this captain
had for passengers one beautiful young lady and ten
young gentlemen. During the voyage the ten young gen-
tlemen became mad in love with the beautiful young
lady, and all of them proposed for her. The contest
between the rival suitors assuming a most violent form
the young lady asked the captain's advice as to bow she
ought to act under the difficult circumstances of her posi-
tion. Tho captain advised her to take him she liked the
best; but the young lady said she liked them all equally
well. Tho captain then hit upon this expedient to
msoolsr-neitnlig neaci difficulty ; he told her to come on deck the next
(the weather being very fine) to plunge over,
board ; that he would take the necessary measures to rescue
her ; and that the young man who would first jump into the
sea after her should be the one that she should select for her
husband. The young lady did as she was advised, and nine
nut of the ten young men immediately pluugled in after her
When they were all drawn up on deck the young lady
asked the captain what she was to do—how she was to
choose one—as the whole nine had plunged iu after her
and stood before her all equally wet from the same bath?
The captain then said, " Take the dry ono"—(laughter)
The young lady acted upon the captain's advice, and the
couple lived very happily together (laughter).
ARISTOCRATIC NOTES.--it is stated that the
Marquis of Bute has purchased Louden Castle, in Ayr-
shire, the seat of the Marquis of Hastings, for the sum of
£350,000. We understand that Mr. Naylor, of Hooton,
has become the purchaser of the residence of the Duke of
Hamilton in Arlington-street.--Echoes from the Chubs.