New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1876-10-09
APPLIED SCIENCE.

increased by the addition of borax to the water.
According 60 his statement, much as 10 parts OF
the acid may be dissolved in 100 parts of water
provided parts of horaX are present Inc presence
OF the last-naned substance 10 IS also anned, dot5
not IN the least detraCt from the value OF the aclu
for surgical uses.
FRANGDILITY OF TEMPERED GLAss.-lt 10 now
affirmed that the Bastie glass, which Is undoubted
hardened by tcmpcrng, loses its molecular cohcsoh
undera succession of blows, and then fractures as
readily as ordinary glass. Tempered glass submit
ted to hammerng presented an appearance on l@tic-
tme similar to that of fatigue steel, molecular ans
indignation having taken place, 1t IS feared thaf
this alteration OF structure and cOhSeq9ehO loss Oh
temper may not only follow from shock, buJ may
happen spontaneously IN the lapse OF tIne'
PGrssURE GAUGE TO ROOSTER $1,000 PoUNDs
"A mechanical novelty worthy Of being placed on
record IS a mercury column pressure gauge lately
completed 10y Thomas Shaw of Philadelphia for
company IN that city which is capable Of register
irg pressure Of "a 600 pounds to the sqlare lnch
The body of this gauge was forged solid from the
best Mdvale steel and bored aud turned to the
proper shape. The total hight is SIX teet th9t OF
The mercury column being four and a half icet
The area of the large pungcr Is SIX aud nan lnces
and of fbe small one thrCeSiXtecnths. and the move
ment about One-thOUsandth of an inch NO gauge
has yet been built 10 register so hsh range u
pressure as this one.
A NEW EMERALD GWEN.-A new pigment, winch
is said to approach the we-luown Paris green IN
beauty. and to have the merit Of being vastly less
poisonous, is said to be bydrated oxide OF chro-
mium. prepared in peculiar manner, and known as
Guicnets green. 1t is prepared by fusing together
on the hearth of furnace, at dark red neat
9 parts boracIc acld and ] of bl-chromate OF po-
taSsium. The result of this fusion Is d3uRIe ttL
b0rate of potassium and chromium which, ny re-
neafed washngs i'm boiling water is deconposed the
b0Tate of DOT asSium Is removed by SOLUTION td'i'
ahydrated oNde OF chromium oenn', c h,S Neil
net possesses very line shade on green Vl"i 49,
ana ressts the action OF ar ana hght qu''c ouoo'"
ally.
Ammonium NITRATE.-Tis extraordinary sub
stance las been reinvcstigated by Berthelot, VINO
obtained it by double decomposition from ba1um
nitrate and ammonium sulphate. The Uttered solu-
ton. eyaporated over quckGme IN yacuo, yei0b
CRYSTALS of the substance desired 1t is also ioneu
bv the simultaneous reaction upon each other OF
nitrogen tetroxide dry AMMONIA, and oxygen IL
forms a white crystalline. dclquescent salt, having
oclior elastic properties 1t decomposes slowly at
ordinary temperatures; at co. to !Q0 cehtgtade IL
explodes violently under severe 6lowlt detolles.
In solution the salt, ANONYMOUSLY decohpeSes HluIe
rapidly than when dry; heated, torrents OF nltIoiGn
are evolved 1t seems to be one OF the IeaSV sl"oe
bodies known.
A NEW PArER PROCEss.-A recent English patent
for preparing paper stuff into new material to be
used as a substitute for wood, leather, and other
materials in a variety of uses, consists in forming
the fbrous materials into paper i'll the usual way,
with as little bleaching and pulpng as possible so
as not TO destroy the fiber. As the paper so manu-
featured comes from the rolls il is taken with MT
terial either of vegetable silk or wool, which has
pasSed through cardng machine, but not pulped,
and the two materials are passed together through
rolls and blended together by pressure into one
sheet ANY number of layers that may be desired,
according 10 the which 1t is TO be subsequently
nut are then incorporated one on the other by by
draulic or accumulative pressure.
S,ITyTrC PLAsTIC.-A plaster Of this descrip-
ton which is said to be successfully employed IN
Edinburgh, is prepared from mixture of hydraulic
lime gypsum, and siliceous sand. The method Of
preparation is as follows: Any fair hydraulic lime
stone is cacined and mixed with about five per cent
Of dehydrated gypsum. After grinding TO fine
powder. this mixture is made into a mortar with
about five or six parts Of clear sharp sand and with
out hair. When laid on as a plaster our account
afirms this cement sets, dries, and har0ens within
2 hours so that q second coat can be laid on on the
second day. and houses thus plastcred are ~ Tor I'M
mediate habtatiOn. This preparation, furthermore,
is represented to be mieTyloIs TO moisture ana 1t
subject 10 breaking or blisterng, as Is frequently
the with impe1octly siaked iilhc' US coSt III
Edinburgh Is said to be no greater than that Of
ordinary mortar.
A NEW StFETY-LAMP-A. paper on "Landau5
new Safety-Lamp for Use in Mines" was lately read
at meeting Of tire North Sta1Ordshirc Mining lnst-
tutc The chief popularity Of the invention RESIDES
i'm the feature that the admission OF gas eXtIu-
cuisines the fame so that il cannot under any cir
cumstances be exploded by the lamp. The whole
Of the air supply that feeds the flame must pass
through an air-chamber in a limited space at the
bottom of the lamp and as soon as the impure air,
such as hydrogen, carburetted hydrogen, &c, fills
M TO that limited space the passage Of the needfll
supplv of oxygen to feed the fame is choIed there
BY. and the fame is necessarily extlnglished for
want Of air. Experiments made to demonstrate this
claim were quite successful 10 was luIIhci CIalIV,,
that the lamp could not be affected by the strongest
current of pure air. but were less successful But
while the latter experiments did not show the Lam
dau lamp to be inferior 10 Others the former we've
regarded decided points OF superiority III coL-
structlon
a NEW METHOD OF PRODUCING 4 VACUUM
With the aid Of the ar-pump it Is possible TO effect
an exhaustion TO about 2loth Of the ordinary pres
sure. which for all practical purposes is ample. In
the solution Of certain scientific problems, however
it has been found desirable to secure greater de-
gree OF exhaustion than this, and other articles OF
more refined character are resorted TO. OF these
perhaps the most efficient that has been devised is
the method of Nichol, whose method IS to fll and
exhaust twice with carbonc acid after the pump
exhaustion, and then by caustic potash absorb the
carbonic acid that is left. The latest proposition
for this purpose is suggested by PrOfs. TAFT and
Dewar, and is substantially follows 4 quantity
of charcoal is introduced into the vessel or receiver
to be exhausted and kept heated during the opera
ton Of exhaustion, which Is effected with the mer-
cury-pump. When the exhaustion has been carried
AS far as possible the vessel is sealed, the heat is
withdrawn, and the charcoal IN cooling cxeits Its
powerful absorbent properties upon The residue Of
froq WI perfection