Brenham weekly banner. [volume] (Brenham, Tex.) 1877-1907, 1891-04-23
SCIENTIFIC MISCELLANY.
IODINE AS A pETEcTIvE.


ten documents have been communi-
Gated to the Paris Academy of Medi-
cine by M. G. Bruylants. 1t is
shown that when, paper, sized and
calendered, is partially moistened,
then, after drying, subjected to the
action of iodine vapor, the parts
which have been wet assume violet
tint, while those which have escaped
water grow yellow or brown. The
of the coloratiou varies with
the time of exposure to the iodine.
Places where water has previously
fallen and dried may still be detect
ed after the paper is completely
saturated with water, the parts which
were first wet being turned an in
tense violet blue by the iodine, while
the other parts become blue. Even
rubbings, such as those which are
made by bread crumbs and elude
discovery by other methods, are
clearly brought out by iodine vapor,
and erased tracings of a soft pencil
are made legible. TIE certainty of
the results depends much upon
the quality of the paper and the
elapse of time, irregular wetting or
rubbing giving fainter differences af-
ter three months or more than when
the manipulations are recent, and
the indications being less clear on
thinly sized paper.
THE LENSES OF SCIENCE.
At the jubilee meeting of the
Chemical Society, of London, Lord
Salisbury offered these definitions.
Astronomy is largely composed of
the science of things as they prob
ably are; geology consists mainly of
science of things that probably were
a long time ago; and chemistryis the
science of things as they actually are
at the present time. An electrical
journal adds that electricity repre-
sents the science of things as they
probably will be.
A recent discovery by Mr.. u. II.
Marley should prove of great impof
lance from an economical point of
view, and opens a promising field
for further investigation. By asso-
ciating iron salts with with suitable
sensitizers, ne has succeeded in pre-
pairing Photographic films quite as
sensitive as any of the modern gela-
tine emuIsions, and containing no
trace of any silver compound.
HAIL IN CENTRAL EUROPE.
The record of injury from hail in
Wurtemberg for 60 years Q82S-SD
has been investigated by Herr
Butler, The yearly average of days
with hail is found to be 13, July
having the largest number of any
month and June the next. About
092 per cent of the cultivated land
was affected, damage being done to
the extent of 100000. Of IL hail
storm paths made out, one very
often taken is from Scheer to Ulm
on the Danube-45 miles long and
10 wide, The paths are all connected
with the confguration of the ground,
slopes with western exposure suf-
fer more than those with an eastern.
while plains are much less affected
than billy ground. No evidence ap |
pears of increase in the fall of hail |
in the course of decades, and the
aforementioned influence of forests
is not distinctly proven.
A German electrician, Herr Gull
cher, has made thermo-eiectric
battery giving electric power equival-
emit to LOS per cent of the heat en-
ployed and hopes to exhibit at
Frankfort battery which will yield
at least 5 per cent net effect. With
an economical source of heat, he be-
ieYes that his thermo-electric bat
terry will even excel the dynamo
machine in efficiency.
On small surface of about 1901
square metres, at Mont. Dol, in
Brittany, the remains of about a
hundred elephants have been dis
covered. The bones are all broken,
md it is believed that the animals
we're eaten by prehistoric men.
A case of cholera in a dog has
been observed by Prof Ogats, of
Toxic. The dogs vomiting and
ourging first attracted attention,
md after its death an abundance of
he comma bacilli were obtained
rom the small intestine.
FERRoID.
A new artificial stone, which can
De melted and cast in moulds, is
said to be compound, partly chem
cal and partly mechanical of iron,
sulphur and silicon, with more or
ess foreign matter. Its normal
color is dark slate, which can be
modified by pigments. The materi-
Il has the hardness of bluestone,
md can be worked by the usual
|