Spirit of the age. [volume] (Woodstock, Vt.) 1845-1913, 1899-03-04
SCIENTIFIC AND INDUSTRIAL.

| oS'GN ! iVIS NV INSSo VINLs
| The rapid displacement OF steam by
electricity for running small machines
is illustrated by report that comes
from Philadelphia. Out of a total of
1919 boilers under inspection in that
city, 625 are temporarily out of use,
most of them because small electric
motors have been substituted, current
for the same being furnished by the
electric light companies.
Arthur Schoeni. of Geneva, Switzer-
land, claims to have succeeded in
manufacturing genuine sapphires; not
imitation stones of glass, but pure
b crystallized aluminium. He has been
experimenting on these for fourteen
months, and also hopes to obtain sim
liar production OF emeralds and
rubies. He asserts that the only diff
ference between his products and
those of nature is one of hardness, his
sapphires having only about two
thirds the resisting power of natural
sapphires.
A new cradle crusher is designed to
crush gold quartz and other mineral
stone on the rolling principle. 1t is
claimed that the new machine is SUI
perior to the stamping process, is
much cheaper, amalgamates the gold
on copper plates behind each roller,
and brushes the stone more uniform
in size than is done by the stamps.
The new machine has heavy rollers,
which are allowed to sway freely, and
in their rolling crush the quartz. 1t
takes care of half ton of quartz per
hour.
In the use of compressed air for
motive purposes it has been customary
hitherto to remove the heat of COM
preston before storing the air by pass
ing the air through coil immersed in
water. Thus a certain amount of
energy is wasted. Merrill E. Clark,
of Worcester, has been lecturing on
new system of using compressed air,
and suggests that this cooling opera.
ton be omitted. He would use the
dir Immediately after compression.
Such plan would seem to make
necessary the conveyance Of the com.
pressor land steam engine that drives
lt) on the vehicle to be operated by
the air motor. In other words, the
power station plant would be carried
about with the car or wagon--a rather
impracticable scheme.
An important discovery has been
announced in the French Academy of
Medicine by George Jaubert, who has
been experimenting on how to supply
air or renew oxygen in air for a man
in Theoretically inclosed space like a
diving'bell. The discoverer's hypo-
thesis was that seventy-nine per cent.
OF the nitrogen containedin respirable
aid remains intact after twentyone
per cent. OF the oxygen has been con-
sumed, and the same nitrogen, mixed
with new supply of oxygen, becomes
resplrable air when the carbonic acid
and the vapor produced by breathing
are removed. He found that his n.y.
pothesis was correct, and then dis
covered chemical substance, which,
by contact with the atmosphere, clears
vitiated air Of all impure gases pro-
duced by respiration and refurnishes
automatically the requisite quantity of
oxygen. He states that six or eight
pounds of this substance will enable a
man to live for twenty -four hours in
diving-bell.
The inspection of milk and It's
sources of supply is of even more i'm
portance from public health point of
view than the inspection of meat,
since milk is so largely used as the
food Of infants. Milk, Immediately it
is taken from the healthy COW, con-
tains no microbes. Hardly has the
milk settled in the pail than they
abound, SO many as 10000 in one
quarter cubic inch having been de-
tected. The question winch naturally
presents itself is, "Where do they
come from?" From the soiled teats,
from the soiled hands of the workers,
from the atmosphere of the milking
shed, aud from the pals themselves.
They possess the property Of propa-
eating very rapidly. NJ. de Freu-
deurich, of the Berne Laboratory, as
serts that milk just drawn, containing
in one-quarter cubic inch 5000 mi
crobes, seven hours later was found
to contain 10000. After period of
twenty five hours had elapsed 5,O00,-
900 microbes were present in the same
quantity of milk; and if the tempera-
ture be raised to ninety-five degrees
Fahrenheit the microbic population of
the same milk during the same time
would reach the enormous total of
S12, 100000. Children appear par
ticularly prone to contract consump-
ton through the agency of milk con-