Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1889-01-13

whatever, provided the substance be not
very heavy. With such conditions of sands
on the beach, it is only necessary that they
be moistened by the sea or rainwater, and
that the moisture be then evaporated. In
the process of evaporation air is drawn In,
making between the grains of sand an elas-
tic cushion. Thus cushioned, the particles
of sand are free to vibrate when rubbed by
the foot or other MEANS The Investigators
found that if the air was shaken the sonor-
BUSINESS was destroyed, and also their in.
quiries seem to show that the particles of
dust or silt block the grains in such FASH
ion that they are not free to vibrate. The
explanation is on its face more satisfactory
than any which have hitherto been proposed
to account for this phenomenon. The in
quirers now propose to make a sonorous
sand, and thus complete the veriication of
their hypothesis.
TYPHOID FEVER IN WATER.
Dr. Charles Smart, surgeon in the
United States Army, holds, with all those
who have studied the subject, that filters
composed of masses of sand through which
the water is forced, though they may afford
water apparently of the purest kind, really
do not serve to separate the poisonous ele-
ments from it. He cites a number of i'm
portant instances which have bearing on
this point He notes the fact that in the
case of the poisonous water which bred the
dreadful epidemic in Plymouth, Pa, where
II of the 5000 people were affected by
typhoid fever, and 130 died from the dis
ease, the water was passed through three
storage reservoirs on its way to the dlstri-
button pipes. In a similar epidemic at
LauZun, in Switzerland, the germs had
passed through what seemed to be perfect
filters. His conclusion is that water which
has once been contaminated can never be
made safe for use. This appears to condemn
the taking of water from any stream which
has sewerage discharge in 1t at higher
point in the stream.
What appears to be conclusive evidence
on this general point is derived from the
history of typhoid fever in Vienna. While
that city took water for domestic supply
from the Danube the annual death rate from
this fever amounted to $40 in each 100, 900 of
the population. After the supply was
changed so that the water was taken from an
upland mountain stream, the death rate
from this disease quickly fell to II in 100, 900
of the population. DR.. Smart states that
10000 people die of typhoid fever each year
within the limits of the United States. If
we allow that the average death rate is one
in ten of those prostrated by the disease, we
have an appalling amount of illness due to
this malady. The probabilities are that
the average death rate is 1 in 15, or perhaps
even less, so that something near 500, 900
people probably undergo each year long
period of illness and consequent enfeeble-
ment of body owing to the disease.
If it be true that water of a safe quality
cannot be obtained from any stream which
has been polluted, the matter has an i'm
portant bearing upon the condition of most
of our cities. In the Mississippi valley it
is extremely difficult to secure water supply
for large municipalities which is safe from
such pollution; indeed, in our American
towns generally, we may say that not one
fourth OF those which have costly systems of
supply have effectively guarded themselves
against this danger.
PROF. N. 8. SHALER.