The citizen. (Frederick City, Md.) 1895-1923, 1897-04-30
written for the Citizen.)


and the diastase of malt are examples.
1t has been regarded as well estab-
lished fact that alcoholic fermentation,
or the transformation of sugar into car
bonic acid and alcohol, depends upon
the presence of the living yeast-cell.
DIR. Z. Buckner, a German biologist,
has now proven that this is really not
the case, but that liquid expressed
from crushed yeast and water excites
fermentation in cane sugar, the action
seeming to be directly due to a sub
stance-an epZyme-eXcreted by the
living organism instead of TO the living
cell itself This substance, believed to
be of a proteid nature, is to be called
"zymase.n The discovery promises to
prove of great practical, as well as sci
entific, importance, as it may be ex-
pected to lead to the commercial pro-
duction of a substance more satisfac-
tory aud reliable than yeast for pro-
ducing fermentation.
Twenty years ago German physic-
list produced heat-indicating paint
consisting Of double iOdide of copper
and mercury, which turns from red 10
black on being heated to go G.. 2070 +. J
Experiments with this were shown the
other day to the London physical So
ciety by Dr. ;. p Thompson. The
paint may be used to coat paper, which
heats quickly bt fore a stove, and if the
paper have designs in black and gold
on the back, they appear in red aud
black on the trout, according To their
respective absorptive powers. Local
cooling by the hand yields silhouette.
In COOLING the paper the silhouette van
ishes, to reappear on reheating, the pa
per thus showing a kind of thermal
"memory." A yellow double oxide of
silver and mercury is even more sensi-
tive, turning dark red at 450 G..
Tests of a parasitic fungus in Cape
economy promise an effective remedy
against locust swarms, large numbers
of the insects having died few day :
after Infection of few specimens.
From observations by DIR. William
Crookes during a recent visit, it ap-
pears that the five mines of Kimberly,
one with an area of 45 acres, are all
contained within a circle 81 miles in
diameter Other deposits, too small
| and too poor to work, are known,
and mine 40 miles away is worked,
while valuable deposits may have re-
manned undiscovered, as no surface in
"a
may exist. The mines are irregularly
shaped round or oval pipes, whose sides
extend vertically downward to an I'M
known depth. They are said To be vol
canic necks, which have been filled
from below with such a heterogeneous
mixtHye of 6lrrounding, underlying
and local rocks as hardly exists any
where else on the globe-fragments of
shale, various eruptive rocks, boulders,
and crystals of many kinds of miner
ais, all cemented with hard, blush
clayey mass. In this breccia-the ia
nous blue clay or blue ground, yellow
ed near the top by oxidation of the
iron-the diamonds are hidden, the
pipes themselves being buried under 10
or 20 feet of more recent deposits. More
than so different minerals have been
been detected by Moissan in the blue
ground. No signs of high temperature
are found in the breccia, while fresh
water shells have been discovered at a
depth of 100 feet, and it is concluded
that the eruptive force was steam or
water acting under great pressure. The
pipes We're certainly not formed in the
ordinary manner of volcanic eruption.
The diamonds from the different mines
have distinctive character, and the
yield varies in different parts of the
same mine. The workings are now
underground, the main shaft at the De
Beers mine being over 1900 feet deep.
Up to the end of 1892, $500, 900, 600
worth of diamonds had come from
these mines, yet this blazing mass of
ten tons could be packed in box five
feet square and SIX feet high. In the
year ending June, 1895, there were
found 2, 435 .54l4 carats Of diamonds, re-
alizing upwards of Sl5,000,000, with
profit of 100000. Large diamonds
arc less rare than is generally supposed,
those of an ounce being not uncom-
mon, while the largest Kimberley dia-
mond weighed 42Sl carats, or nearly
ounces. and the largest diamond
known weighs $40 arats.
The advan; ages, of acetylene for mo-
tor-carriages have not been overlooked.
The acetylene motor now being built
to the design of NJ. Ravul Pictet will
have three cylinders, and will develap
ten horse power while occupying small
space.
Self-toning printing paper is nov
city that amateur photographers Will
appreciate. 1t is prepared 10y coating
the paper with "a collodion emulsion
mixed with the silver and the toning
chemicals, and when printed behind
a negative III the usual way it gives dl
rectly the color OF ordinarily finished
prints instead of red color. The print,
when tritle darker than is desired,
is fixed in the usual hyposulphile of
soda solution. The prints are said to
equal those made in the ordinary way
III appearance, and to be quite as per-
manent.
Evidence of the value of respirators
in working in dusty atmosphere lave
been noted by the French Northern
Railway Company. A man employed
in the company's paintgrindlng mill
for 33 years had been on the sick list
about month every year, but since
being supplied with resplrator in
1885 he has been able to continue at
work without interruption. This is
given as asiDgle Illustration of the gen