Scientific American Supplement, No. 664, September 22,1888Various
History
Scientific American Supplement, No. 664, September 22,1888
Various
Science -- Periodicals
An objection may possibly be raised to this modified method, viz.,
that albumen as ingested is not in the form of a dry powder, and that
we ought to copy as nearly as possible the conditions existing in the
stomach. To this I would reply that it does not matter in the least,
to us, as analysts, what are the conditions which obtain in the
stomach; since there is no absolute test for pepsin, we can only
compare one sample against another, and that which dissolves the most
albumen in the shortest time is taken to be the best.
Another imperfect method of analysis is that employed in the
examination of malt extracts for diastase, in which a certain weight
of extract ought to dissolve a certain weight of starch in ten
minutes, when if it does so dissolve it, the extract is a good one; if
not, it is to be condemned. The more correct way is to ascertain the
reducing power on Fehling's solution, before and after digestion with
an _excess_ of starch, and I intend to say a few words upon this
subject on a future occasion, when I have ascertained the maximum
amount of diastase existing in the best samples of malt.--_The
Analyst._
* * * * *
SUBTERRANEOUS FLORA AND FAUNA.
By Dr. OTTO ZACHARIAS.
It is generally correct to say that air, light and moisture form the
chief conditions necessary for the development of organic plant or
animal life. One of these conditions, however, namely light, is not of
equal importance with the two others. For modern investigation and the
discoveries made during the progress of natural sciences have shown
that in the depths of the ocean, where an everlasting darkness reigns,
and where the temperature is extremely low, nevertheless a great
abundance of animal life is to be found, and that there exist living
beings, not only of the lowest organization, but even fishes and
crustaceans of very complicated structure, all of which thrive without
enjoying the slightest ray of light.
A similar example of animal life in the absence of light is to be
found in the fauna of caves and grottoes. This was first made known to
the world by Austrian and American naturalists. The well known
Adelsberg grotto in Krain, and the gigantic Mammoth Cave in Kentucky,
furnished much interesting material for a detailed study of the
biological conditions of subterraneous animal life. It was gradually
discovered that in those dark places there existed not only insects,
spiders, crustaceans, centipedes, worms, and snails, but also a kind
of salamander and fishes. But what gave special interest to these
discoveries was the fact, ascertained by careful study, that not all
of these beings were gifted with normally developed organs of vision,
but that in some these organs had undergone a retrograde development,
while others were entirely blind.
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