The evening times., 1898-09-09

one that he was expelled from the uni
versity for marrying, and that. being
very poor, his wife was obliged to con-
tribute toward the housekeeping by knit
ting. 1t was while watching the motion
of her fingers that he conceived how to
initiate these movements by machine.
Arkwright accidentally derived the
idea of spinning by rollers from seeing n
redhot bar elongated by being passed be-
tween two rollers.
The ordinary practice of taking bath
solved the Archimedes the question OF
how to test the purity of the gold in
Heiro's crown. He observed that when
he stepped into a full bath the quantity
of water which overflowed was equal to
the bulk of his body. and 1t occurred to
him that the worth of the crown might
be tested by such means. He thereupon
made two masses of the same weight as
the crown. one of gold. the other of sill
yer. and immersed them separately in a
vessel filed to the brim, measuring eN-
actly the quantity of water that over
flowed in each case. Having found by
this means what measure of the huid an
swered to the quantity of each metal.
less in the case of the gold than of the
Silver-the bulk of the former being less,
weight for weight-he next immersed the
crown itself, and found that it caused
more water TO overflow than the gold but
less than the silver. Having found the
difference between the two masses of
pure gold and silver, in certain known
proportions, he was able to compute the
real quantity of each metal in the crown,
and thus discovered the fraud that had
ben practiced on the king, to whom he
hurried. eXciaining, "Eurekai Eurekai'
CT have found it, l have found it!0
an exclamation that has ever since been
used to express exultation over a diScov-
cry.
Coming down now to our own time,
the account of the discovery of saccha-
rine one of the numerous by-products of
the gas-maker's refuse, whose sweetness
is three hundred times more intense than
that of cane sugar, reads almost like
romance.
DR.. Fahlberg has entered the Johns
Hopkins University in America in order
to devote himself exclusively to study
of the chemistry of coal tar derivatives.
Some months had passed when, one
evening at tea time, he detected an in
tensely sweet flavor upon his bread and
butter He traced the sweetness to his
fingers to his hands, and to his coat
sleeves, and it dawn upon him that 1t
must have been derived from one of the
new compounds which he had that day
succeeded in producing. He promptly re-
turned to his laboratory and tasted the
contents of every vessel with which he
had been working His idea was correct
One of his beakers contained the sweet
material.
Prof Roentgen came upon his marve-
Ious X-rays-which have opened out new
fields of research in physical science, be-
sides being of far-reaching practical util-
ity in surgery and other departments
quite by chance. He was experiment.
ing in the dark with a Crookes vacuum
tube which was covered with some sort
of cloth A strong electric current was
passed through 1t, while close by was
some prepared Photographic paper, but
no camera. Next day he noticed several
lines on this paper for which he could
not account By restoring everything to
exactly the same condition as on the pre-
ceding day, he was able to ascertain the
real origin of these mysterious marks.