On the brightest and sunniest day, millions of tons of black
charcoal in an invisible condition are floating in the air.
Millions of plants are at the same time restoring it to visible
form by the chemical processes going on in the tiny laboratory
of every leaf that expands in the sunshine. In the course of
time the leaf or the wood it elaborates by its delicate alchemy,
may be burned; and this cycle of change may go on indefinitely,
the matter becoming visible and invisible again and again.
(Text.)--_Popular Science News._
(1675)
* * * * *
In chemical operations, whether natural or artificial, matter
is often “lost to sight”; but the veriest tyro has learned, as
one of the fundamental axioms of science, that it can never be
actually lost or destroyed. In its manifold mutations it often
disappears from our vision; but it reappears, or can be made to
reappear, as palpable to our senses as before. If a piece of
silver be put into nitric acid, a clear and colorless liquid,
it is rapidly dissolved, and we “see it no more.” The solution
may be mixed with water, and apparently no effect is produced.
Thus, in a pail of water we may dissolve fifty dollars’ worth
of silver, not a particle of which can be seen. Not even the
chemist, unless he should apply certain tests to detect its
presence, would, by merely looking at the liquid, guess what
hidden wealth it contained. Other metals, as we know, can be
treated in similar ways with the same result. When charcoal and
many other substances are burned, they disappear as completely,
no visible ashes even being left from the combustion. In fact,
every material, which is visible can, by certain treatment, be
rendered invisible. Matter which in one state or condition is
perfectly opaque, and will not permit a ray of light to pass
through it, will in another form become perfectly transparent.
The cause of this wonderful change in matter is utterly
inexplicable.--_Popular Science News._
(1676)
* * * * *
The progress of science is fast bringing the hitherto invisible
universe into man’s view.
Unofficial announcement has been made at Boston that Prof.
H. C. Ernst, of the Harvard medical school, has discovered a
new method of photographing bacteria, which makes it possible
to watch the life of disease germs, to watch the effect of
medicine upon them and to see new facts as to the form which has
heretofore been clouded in mystery. The Ernst method consists in
the use of ultra-violet rays of the spectrum which are invisible
to the eye. Under the present method no picture of germs is made
until they are colored by chemicals.
(1677)
=Invitation=--See HELP FOR THE HELPLESS.
=Inward Rectification=--See TRANSFORMATION BY RENEWING.