The San Juan islander. [volume] (Friday Harbor, Wash.) 1898-1914, 1903-11-26
EklnssSCience7
NsGsslllveantion


perature far above that ordinarily gen.
Grated for smelling ores and metals. 1t
Is therefore proposed as coating for
fire bricks, to be applied as a paste
with sodium silicate, and tests have
shown that twelfth-inch coating pro-
tects the bricks from the creates theat
of ordinary work with metals.
The diving apparatus of Slgnor Pine,
an Italian engineer, consists of kind
of globular boat provided with deli
cately jointed mechanical arms, and
with this 1t is practicable to reach the
sea bed at depth of 100 yards, and
to perform any kind of work. In
test near Genoa, the inventor descend
ed to the bottom and returned with
the greatest ease.
Alloys are usually more fusible than
the least fusible metal contained, and
they are almost always heavier or
denser than the average of their I'M
combined constituents. A remarkable
1887 per cent Of aluminium and St13
per cent of anthony. Both metals
melt at about $50 deg. c., while the
alloy requires a heat of 1880 deg. c.,
and the specific gravity Of the latter
Is only 4,21S-instead Of 5,225, which
it would be If there were no change
of volume. In other words, 7.07 cubic
inches of aluminium and 1907 Of anti.
mony produce 23.71 cubic inches of al.
10y.
1t is suggested in the October, 1902,
Bulletin of the Trinidad Botanical De-
partment that pitcher plants, which
possess the property of capturing and
killing insects that venture into their
flowers, could be proftably employed
in preventing the ravages of cock
reaches among orchids. BY inter-
spersing the pitcher plants among the
orchids 1t Is believed that the orchids
would be, to great degree, protected,
because the pitcher plants have an at
traction for such injurious insects as
cockroa ches, and seldom let them get
away. The pitcher plant fiourishes I'M
der conditions of heat and moisture
quite similar to those that are most
favorable to orchids.
1t has been found that the bacterici-
dial effect Of the arc-light Is much SUI
perior to that OF sunlight, because the
very rapid ultraviolet radiation from
the sun is absorbed by the atmosphere.
A rapid oscillation high-tension are,
particularly when formed between iron
points, gives off an abundance Of ul-
traviolet rays Of extremely short-wave
length. Quartz Is transparent to this
light. of which it transmits 60 per cent,
but gelatine and an oxide of iron, even
thin film Of it, are entirely opaque.
Ice is as transparent as air to these
rays, but blood is Opaque, and accord
ingly, in applying them to the human
body, they are passed through ice
pressed upon the region affected so as
to make it bloodless.
There Is a platinum problem" as
well as coal problem, and writer In
Science says it has become a very
serious one, because while the demand
for this metal has rapidly Increased
during the past few years, the supply
has been diminishing. Mines contained
in two small districts in the Ural
Mountains have long been the worlds
chief source Of platinum. Two Rus
sian families, the Demidoffs and the
Shouvaloffs, are the principal owners
Of these mines. Recently rich find
Of platinum has been reported In the
more northerly Of the two districts, at
Gorobla godatsk, along the River ISIS
and its tributaries. Formerly some of
the sands produced as much as one
ounce Of platinum to the ton, but late
ly this has been reduced to one or two
pennyweights. The new diggings are
said to rival the richness Of the older
sands.