The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1907-12-21
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.

Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.
Water from Granite-seeing Ones Own
Bye-A Microscope for Oomfort-A High
Vacuum from Lirne-An Improved Soap
The New Diphtheria Cure-Electric
Anaesthesia-R the Deaf to
Hear-Cheaper Meat.
Experiments show that while the sedimentary
rocks may absorb several per cent. of their vol
ume of water sandstones Is per cent. lime
stones per cent. and shales per cent.-gran-
ties and other crystalline rocks seldom absorb
more than one-haf of one per cent of their vol
ume and until within few years it was thought
to be absurd to sink well ia the harder rocks.
Frederick G.. Clapp. of the q. s. Geological Snr-
vey, has now reported that about 81 per cent. of
the wells In granite In southern Maine supply
water enough for domestic use. Water percol-
ates very slowly through the rock but more
sinks into the vertical joints. and moderate
quantity is stored in the horizontal joints and
crevices down to depth of 200 feet, the amount
being so limited that only two out of Y success
full wells yielded more than 30 gallons per min
ute. The wells are drilled only in the surface
rocks, two-thirds being not over 100 feet deep.
~
novel apparatus to enable person to study
the internal structure of his own eye is the
device of French oculist, DR.. Forth. The
light of a mercury vapor tube is reflected by
highly polished mirror through two thicknesses
of blue glass to lens and this concentrates the
ray upon the eye. From.a suitable point be-
hind the lens, the observer sees the circulation
Of the blood in the minute vessels of the eye,
with other details. When a card pierced with a
pinhole is moved rapidly to and fro in front of
the eye, the fovea. the little depression at the
most sensitive part Of the retina is made visible
-
The use of the microscope in the upright posi-
tion causing much fatigue, A. A. G. E. Merlin.
an English microscopic, has designed new eye
piece, which has prism enabling The observer
TO look through the tube from the side instead
of the top.
The water in slaked or hydrated lime is given
on on moderate heating. and by causing the va
por to expel the residual air In the receiver of
an air pump and then cooling the lime so thatit
reabsorbs the moisture, an excellent high vacu-
um-which may be greatly varied by gently
heating the lime-may be cheaply and quickly
obtained. Prof. A. Henry, the French physicist,
believes that this simple process will prove
valuable for industrial purposes as well as in
the laboratory. In his experiments the receiver
was connected on one side with glass bulb con-
tanning about 30 grammes of slaked lime and on
the other side It was connected by waterfall
sorbing tube with an ordinary air-pump and
after the air had been partially pumped out the
temperature of the lime was raised to 1902 G: by
an alcohol lamp. After about four minutes the
receiver was sealed on the air pump side. The
lime soon absorbs the water vapor left in the
receiver. and If the electrodes of an induction
coil have been attached to the receiver the va
cuum is found to be sufficiently high to produce
cathode rays, while slightly heating the bulb to
lessen the tension will give various other phe-
nomena, including those of Geissler tubes.
sss
new detergent, known as ..Tetrapol." has
been attracting favorable attention in Europe,
and is claimed to haveladvantages in securing
woolens and all kinds of textile goods. The
household soaps claiming increased efficiency
through the presence of hydrocarbons usually
contain petroleum naphtha not exceeding five
per cent. Tetrapol, is yellowish liquid. and is
found to contain So per cent. of water, % of
.Monopol soap'' in place of ordinary soap, and
20 of carbon tetrachloride. the special solvent.
"Monopol SOAP" the fatty base, is a red oil hav-
ing the popularity of solubility in hard water.
-
Pyocyanase serum, the discovery of Prof. En-
merich. of Munich, is claimed to completely de-
stroy diphtheria bacilli-even in the severest
cases-when sprayed into the patients throat.
s"s
The electric current by which Prof. Leduc
produces anaesthesia is unidirectiona, not alter
mating 1t is of low voltage, and he has found
about 100 Interruptions per second by special
commutator to be most effective, although an
apparatus repeating his experiments at Column
bia University gives 1000 to 5000 interruptions.
suitable than that from street mains. With
curved and padded electrodes. at the front and
rear Of the head, gradually turning on the cur
rent frst causes excitement, as with the appli-
cation of chloroform. and slow increase of cur
rent yields Inconsistencies with no movement
or sign of pain. Any operation can be perform
ed. Awakening is instantaneous when the cur
Rnt Is cut of, and vomiting and other unpleas-
an6>after effects of chloroform entirely abb
sent. In the one trial thus far made on human
subject-tnat on Prof. Leduc himself-the ex-
pertinent was not carried to the stage of COM
plete anaesthesia.
In the experience of DR.. Marage, as reported
to the Paris Academy of Medicine. very few
deaf-mutes have proven absolutely incurable,
but of the others there are two classes-those
who eventually understand and speak almost as
well as anybody, and those who get no further
than hearing and understanding music. A re-
. cent class of pupils from eleven to fourteen
years of age had been given a six weeks course
of acoustic exercise with the voice siren. BY
this system the teacher avoids fatigue, and the
children had not only acquired the ability to
hear and understand French, but their voices
had lost the harshness Characteristic of deaf
mutes.
Horse flesh has been priced as food in China
for six centuries, but in Europe was first eaten
100 years ago by the Danes. At Liege, Belgium,
1000 horses were slaughtered in 1905, and the
rapidly increasing demand promises to open
new market for American horses. Only young
animals are sent to the slaughter houses