New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1875-10-16

| PREPARATION or CHROME-GREEN.-AccOrdiDg 10
| Casa O very beautiful chrone-greeD which Is read
| ily fastened upon fabrics, and meets all technical
requirements may be simply and cheaply prepared
by ignitng strongly an intimate mixture Of one
part of bichromate OF potash and three OF c9clned
| gypsum, and boiling the mass obtained with very
dilute hydrochlOric acid.
| An,pr,TIoS OF TIE STRUCTURE OF ANIMALS 10
THEIR NEEDs-The expansion Of the sides Of the
body in animals as a support while moving through
the air. is an adaptation found in various classes.
The nying squirrels and pterOsaurs are well-knOwn
exam pies among mammaa. The lizards Of the
Cenu, Draco represent II among reptiles. The
batrachans possess a modified representative IN
Walace's Rhacophorus, where the webs Of the toes
are so dlated as to resemble parachute. Mr.. Cam
bridge describes a spider from Australia which ~
furnished with parachute. This specas-the S0ti-
Gus roldns-has the integument of the sides OF the
abdomen extended into horizontal membrane.
cOncaye below, the upper surface OF when IL Drll
liant metallic green. The saltci are great leapers.
and the expansions in question serve support in
long jumps from tree to tree
NEW METHOD or REMOVING HAIR FROM HIDES
Until quite recently the usual method of removing
hair from hides rs a preliminary to tanning. con-
sisted either in inducing slow puirefaction, which
l0osens the epdermls and renders the hairs easily
separable or else placing the hides in large vat
containing milk of lime. After number of days
the hair was readily removed by blunt scraper At
present however in many parts of Europe, these
methods have been abandoned in favor Of one in
which the sulphde Of lime is the main agent-this
salt in crystalline form, being now manufactured
for the purpose in Germany Sometimes, when it il
desired to remove the hairs quickly posi- BILE, as
in the case of sole leather, the hides are painted with
paste consisting OF one part OF crystalllzed suplde
Of sodium and three parts OF lime. The hides arc
covered with damp mating to prevent the drying OF
the paste, and in II or 20 hours the process ~ COM
pete, and the hair can be removed. In other cases
when more time is allowable, the skins are stepped
IN a solution of sulphide of sodluInl pound TO 100
quarts the effect being accomplished in two or three
DAYS. Where the hair is to he removed from the
hides by hand, 1T Is necessary that they be well
rlnsed in water; and the men employed IN laying on
the paste usually wear india rubber gloves while
handling the nldes
LUTING FOR GAS misunderstanding to a COM
municaton by Capitainc, many of the cements for
gas retorts recently introduced into the market con-
tain soluble glass as the iux He contends. how
ever that soluble glass is only available for this pur
pose in the form of the fine white powder obtained
by fusing and puyerizing it. A mixture Of this
with three to four parts of clay forms lutte that
be used. All attempts to employ liquid water-glass
with clay. chalk, sulphate Of baryta, and similar
substances have proved unsuccessful, since the mix
lures harden in short time, and consequently can
not be kept if the water-gass Is very rich in
alkali as is that manufactured in England. An ex-
y,
and which is always fit for use, may, however, be
prepared by mixing suitable meager clay, as China
clay, with solution of caustic soda or with con-
centrated solution of carbonate of soda, about 10
per cent much of clay OF the former, OF 20 per
cent the calcined carbonate, being necessary the
exact quantity depending, of course upon the re-
fractory character of the clay. Caustic potash and
carbonate of potash answer the same purpose, but
are more expensive than the soda. Scaly 5 cement
is said to be nothing but a mixture OF emma clay
with caustc alkali.
l..
given in Paris to a new lamp, the invention of
Messrs b. Delachanal and A. Mernet, and intended
for Photographic and other purposes where a bril-
liant light is required. Carbon-5ulphide and bnox-
ide of nitrogen are employed Ignition of bmoxIde
of nitrogen, containing vap0r OF carb0n-sulphdc,
produces brilliant flame of a yi0let-bue tint, pecu-
liarly rich in chemical rays. The carbon-sulphde
lamp by which this flame is produced continuously.
is constructed simply of flask with two tubulures.
the vessel having about 800 cubic centimeters
capacity. The flask is filled with spongy fragments
of coke or, better. of dried pumce which imbibes
the carbon-sulphiGe Through the central tubulure
passes tube to within short distance of the bot
tom in the other mouth or tuhulure is fixed tube
of large diameter, about 20 centmeters in length.
The latter is Of glass or metal, and contains an
arrangement acting as safety-valve, as
well as impeding return of the gas and
preventing explosion. Binoxide of nitrogen
is passed by this tube into the flask,
and the gaseous mixture Is conducted by caout-
chOuc tub. to kind of Bunsen burner, from which
has been removed the airport and the cone regu-
lating the supply of gas. The bnoXide of nitrogen
is produced by Claire Deyille apparatus, but in
stead of dccOmp0sng nitric acid by copper. which
would be too expensive, mixture of nitric and
suphuric acid is caused to act upon iron.
The flame, which is about % centimeters in hight.
possesses high phOtogenic properties, and is much
superior to the light obtained from the magnesium
ribbon The apparatus is nearly as portable, the
mixed acids being contained III one vessel. which
communicates 10y tube with vessel containing
fragments of iron. Supply Is regulated by cock.
The flame is constant, unlike that of the electric
light, aud Is not subject to spontaneous extnctons,
like the magnesium lamp. photographs ofhulnan sub
jects obtained in less exposure than II seconds.
Phot0metrc tests show flame for iiame, per measure
about twice the power of the hydrogen light.
The inventors have been studying the question of
DEVELOPMENT of the grcen-cOloring matter of plants
by means of this light. making their experiments IN
VI. Dumas laboratory at the Central School of
Paris
MECHANIcAL Production or CoID.-The pro-
ducton of cold by means of mechanical operations
distinguished from cooling by radiation
ducion. has never been accomplished in SO thor
Oughly practical and satisfactory manner as in the
great pamffne oil works at Bathgate, Eng In order
to extract the solid paraine, it is necessary to cool
down all that portion of the crude oil to a tempera-
ture of 80 to 40o f.. TO the paratine to
crystalline. When the works were in their infancy
this was accomplished by storing the oil IN Summer
and exposing it in fiat dishes to the cold
in Winter. As the works increased, it became
necessary to devise means for accomplishing this re-
suit AT all times of the year. The Harrison ether
machine did good service but it was found TO be too
small. Mr.. A. c. Kirk the engineer of the works,
after learning of the ice-machne of DR.. Gorrc,
which had succeeded in Florida but failed in Lon
don, decided TO follow methods similar TO those
adopted IN that machine The simple plan of com
a IN Al