Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1882-03-25
SPARKS OF SCIENCE.

Some naturalists in Alaska have found it
difficult to secure skeleton of the sea ct
ter, because the natives believe that when
they kill an otter they must cut off the
head and throw it into the sea or their
canoe will be lost.
De Fosse, of Paris, has introduced pa
per covering for furniture. 1t is made in
imitation OF Cordova leather, and is said to
be so effective in its purpose as to promise
competition with textile fabrics for up.
holstery work.
Special poisons are secreted by the toad,
salamander, newt, frog, etc. M. Paul
, Bert has collected a liquid from the glands
on the neck of the frog which caused the
death, with commissions, of sparrow to
which the substance had been admins
tered.
Some observations were lately made in a
balloon by NJ. de Fouvicle on an opaque
cloud which covered the region of Paris for
several days. The cloud was hardly 300
meters thick. The upper part of the guide
rope was covered with hoar-frost. The
mean temperature of the cloud was 81.
1t ia stated that in Mexico wooden rail
way ties cost about 81 so apiece, and that
some of them laid on the Mexican National
Railway last May are now decayed and I'M
safe. Il is said that it has been found
cheaper to order iron ties, worth So each,
from England, than to use wooden ones.
In coppering cast-iron NJ We'll uses a
bath of copper sulphate rendered strongly
alkaline with an organic acid added to pre-
vent the precipitation of copper oxide. To
effect the same object MN. Mignon and
Rouatt employ distinctly acid solution of
double salt of copper and any alkali with
an organic acid.
To harden steel take two teaspoonfuls of
water, one half teaspoonful of -four and one
of salt. Heat the steel enough to coat it
with the paste by immersirg it in the COM
position. after which heat it to cherry
red and plunge it into soft water. II prop
ery done the steel will come out with
beautiful white surface.
The Munster Zeitung recommends IL
preference to the treatment of glue with
nitric acid the following: So-called gela-
tine is dissolved in the water bath in its
own weight of strong vinegar, a quarter
part of alcohol and very little alum. This
glue remains liquid when cold, and is much
used for cementing mother-of. pearl, horn,
ETC., upon wood or metal.
A new and interesting proof that the
earth is round has been presented by M.
Dufour in paper recently read before the
Helvetic Society of Natural Sciences. In
calm weather the images of distant objects
reflected in the Lake of Geneva showed
just exactly the same degree of distortion
which calculation would predict through
taking into consideration the figure Of the
earth.
Mineral-tanHed leather is impervious to
! water, and is said to be much more durable
than leather prepared in the ordinary man.
ner. Tests have been made which show
that belts of mineral. tanned leather are not
only 80 per cent. cheaper, but are stronger
than common belts. The mineral process
of tanning is reported to have been intro
duced into eight tanneries in Germany.
II piece Of iron appears to have an un
sound weld, or if it has crack apparent
upon its surface, and it is desired to know
how deep it penetrates, heat the part to be
tested to red heat and pour fine stream
OF water on the faulty spot, but mainly on
one side of it, and the iron on that side
will lose it's redness more rapidly than the
other side and plainly indicate how deeply
the defect extends.