The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1895-07-13

the hand which seized it became red, and
developed papules and other indications of
local irritation. A day or two later the eye
became the seat of what proved to be
very troublesome Inflammation, associated
with the presence of rounded elevations,
due to an accumulation of cells around
the imbedded hairs, which were subse-
quently discovered and removed. In
spite of treatment the disease exhibited
the characteristic tendency to periodical
exacerbations and it was many months
before the unfortunate boy had even APP
proximately recovered from the effects. 1t
does not appear to be known with any GER
tainty what particular species of cater
pillar is responsible for these troubles, but
it is beyond question that several varieties
are capable of determining local irritation
when brought into contact with the skin.
1t will be well, therefore, for caution to be
exercised in the handling of caterpillars,
and practitioners may find it worth while to
bear in mind the facts stated when called
upon to treat obstinate cases of recurring
Inflammation of the eyes occurring during
what may be described as the caterpillar
season.
CoRRosIoN OF METALS BY SEA WATER
The difference in the corrosive effect of
water in various harbors is now believed to
be due to the action of micro organisms,
which, infesting some particular harbors,
may give rise to injurious secretions which
are absent in the general waters of the
ocean. Plates of pure aluminium placed
in the Norfolk Roads for three months were
badly corroded at the end of that time.
On the other hand, experiments made in
france showed that commercial aluminium
was practically unattached by sea water,
and IN one instance two aluminium plates
liked to the bottom of a French sailing
vessel were found practically unlnlured
after voyage around the world. With
these facts in view, an examination of
water from different localities has been
made. The amount of salts contained in
sea water varies from 3l.14 parts per 1000
IN the Atlantic Ocean TO as much as 40.7
parts per 1000 near the city OF Marsellles,
France Hence if introduced into boilers
the Mediterranean water is more likely to
cause damage than ocean water. Near es-
tuaries and the shore line generally con-
siderable proportion OF nitrates. is found,
arising from fermentlng organic matter.
Shore water attacks metal plates much
more rapidly than ueep-sea water. If,
however, the shore water is sterilized by
boiling it's destructive qualities are greatly
neutralized, which indicates that the in
furious secretions of the bacteria have been
destroyed.
PHoToGRAPH1NG THE VIBRATIONS OF
PIANoFoRTE WIRE.-Although the piano
forte is the most popular instrument of the
day, it is surprising how many of its pro-
fessional performers fail to make it inter-
esting. This, while to a great extent
matter of temperament, is often undoubt-
eddy due to ignorance of the dynamic effect
of touch" as affecting the vibration of the
strings. A most interesting light has been
thrown upon this subject by series of
photographs taken in Germany of the mo-
ton of the pianoforte wire when struck in
different ways. 1t was found that the dur
alton of contact was longer with feeble
than with hard striking. The most i'm
portant result was the proof that when a
wire is struck at a point between one
seventh and one-ninth of its length the
fundamental tone has maximum. and
the harmonies-especially the third-are
very feeble. Hence wire thus struck
gives its strongest and richest tone. This
is an instructive fact for musicians as a
base for what will be to many of them a
new line of study.
SIMPLE REMEDY FOR Poison IVA cor
writes: GAS many of YOUR
readers are off or going to the country.
where not a few are likely to become VIC
TINS of the poison oak (poison ash and
poison ivy are its aliases) tell them that
the best and almost always unfaiIinp
remedy is crude petroleum as a lotion.
have seen child whose face was terribly
swollen and distorted. and whose suffer-
lngs were pitiable, almost Instantly re-
lieved and kept comfortable until the in.
dammation has passed away"