The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1890-11-29
Correspondence Baltimore County Uni0n.
SCIENTIFIC MISCELLANY.
MYSTERIOUS PICTURES.

MYSTERIOUS PICTURES.
Amateurs in photography and chemical
magic may get much amusement from the
magic photographs described by French
any negatives upon chloride of silver paper,
and are fixed, without toning in gold solution,
in a ten per cent. bath of hyposulphite of soda.
They are next thoroughly washed to remove
all trace of the salt. The prints are then placed
in five per cent. bath of bi-chloride of mer-
curry, in which the images gradually fade and
soon disappear entirely. When the bleaching
is complete, the paper is washed and dried. To
make the latent images reappear, 1t is only
necessary to immerse the white paper in five
per cent. solution of sulphite or hyposulphite
of soda; what is more Elusive, to place the
bleached photograph on sheet OF 6lottlng
PAPER previously saturated with sulphite OF
soda, and dip both in pure water. The chlor-
ide of mercury is converted into black sulphide
of mercury, and the chloride of silver which
has formed in the bi-chloride of mercury is dis
solved.
LOOKING FORWARD.
Of the time when astronomy shall have
telescope of 60 inches in diameter and over 50
feet in length, NJ. Camille Flammarion says: :
ITO what unexpected discoveries would this
supreme effort of your great nineteenth century
lead2 This is question which it is impossible
to answer but we have the right TO dwell on
the word unexpected" 1t must not be for
gotten that it was when searching for the
limits of the colors in the solar spectrum that
Fraunhofer discovered spectral analysis, and
that it was while seeking the parallax OF the
stars that Sir William Herschell discovered the
orbits of double stars, and it was when seeking
for Asia that Christopher Columbus discovered
America. In any event, such telescope will
enable us to see for the first time the seven
tenth magnitude stars, which must be scat
tered over the depth of heaven in carpet OF
5000 stars, while the moon will be
brought, sotospeak, within touching distance"
ARTIFICIAL sKULL-sHAPING.
Astonishing success has attended the efforts
of DIR. Iannelongue an eminent specialist OF
Paris, to give intelligence to little idiot girl.
Though four years old, the child could neither
walk nor stand, and never smiled nor took
notice of anything. The doctor concluded that
the abnormal narrowneSs of the head OBJ
structed the growth of the brain, and in May
last he made an incision in the centre of the
skull and cut piece of bone from the left side
of it. The result was marvellous. Within less
than month the child could walk, and she is
now quite bright-playing, smiling, and taking
notice of everything around her.
ORIGIN OF HOSPITALS.
The latest archaeological discoveries show
that hospitals existed in India as early as the
fifth century before Christ. In Ceylon, King
Pandukabhayo established hospital in his
palace, and one of his successors, in the second
century before Christ, founded eighteen differ
ent institutions of the kind, each with medi-
cal staff and the remedial agents of the times.
The Buddhist King, Asoka, had about the year
$50 B. c., hospitals both for man and animals.
Many other hospitals-now unknown-were
doubtless established at an early period, but the
London Lancet concludes that their work was
much less important than that of the hospitals
which developed in Rome and elsewhere as the
result of the spread of Christianity.
oZoNIZED MILK.
An Italian investigator, Prof. G. Tolomei,
has been studying the wel-known phenome-
non of the souring of milk by thunderstorms,
and concludes that it is due to ozone. When
electricity was applied directly to fresh milk
the souring was delayed, sweetness being re-
tanned from six to nine days, whereas portion
ofthe same milking not treated with electricity
was distinctly acid on the third day. The
electrified milk coagulated exactly like ordi-
nary milk, and not like milk that has been
boiled. Milk exposed to the ozone of Holtz
electrical machine quickly became acid, and
coagulation was also produced IN few hours
when a stream of ozonized oxygen was passed
through the milk. 1t was evident that the
ozone caused the milk to sour, and Prof. Toll
omei supposes that oxygen promotes Tactic fer
mentation.
BoRAcIc ACID FOR CONSUMPTION.
Some very interesting and possibly impor-
tant experiments have been made during the
past five years by Dr. Gaueher, of Paris. Ba-
cilli of tuberculosis were injected into several
rabbits producing the disease in all cases.
Other rabbits were then inoculated IN just the
bran mixed with boracic acid. On killing
these rabbits after time, no trace oftubercular
disease could be found. How far the boracic
acid might be beneficial to the human victim
of tuberculosis is not known, but in such trials
as have been made lung decay has been arrest
ed and improvement in every way has re-
suited.
MISCELLANEOUS.
A recent contract provides for street lighting
in Paris on novel plan. Power is distributed
by the compressed air system to great num-
Der of small motors, each of which supplies
current for small number of lamps
Measurements of q 900 children in Saxony
show that the boys are small fraction of an
year; but that the girls then become taller
until the sixteenth year, when the boys again
surpass the girls in height.
Prof. Cohn, of Breslau, has found that the
heating of hay to the point of spontaneous
combustion is due to a fungus. He first
studied heating barley, finding that the tenn
perature of this is raised about 40 degrees by
the progress of termination, and that rise of
more than go degrees is caused by AspergillaS
funigGtuS, which acts as a ferment.
Crushed steel-made by crushing in stamp
mill high-carbon steel quenched in cold water
from an excessively high temperatures being
used for cutting stone. 1t is very hard, and
cheaper and more effective than emery