New-York tribune., 1873-07-26

an ordinary negative ana the pictures ny '',t "
have q strength and softness unattainabie by
single negative.
PrnIrrcAr1oN or TAIIow-Treutlen states that
taow treated in the following way is almost odor-
less. can be preserved in this condition IN earhen
vessels covered with bladder paper or tight covers
for a long time and can be used for cooking, for
pomade salves. &c: The fresh tallow thoroughly
melted in boiling water is pressed with it while hot
through a linen straincr, boiled oglh, ana cdreIuly
SKINNED then cooled TO Sodllcation, washed WIN
water, and finally carefully freed from water b{
pressure then fused at moderate temperature ana
put in earthen vessels.
CASING rc8 STEAM PipEs, according to r.
Weinlig, the following Is a soryicealle eNtIaolu-
nar.ly cheap and easily prepared substitute ior 'lo
Justly popular Lcroy's composition. Very porous
thick paper Is first wrapped around tEc plP'S az"
fastened with wire, and then coated win u''u''
sugar siup. AmiNtme Of six bushels OF Ci'1'
bushels of sand or better still Of very me coNT
is msdc with a tc water as PoSsinie 5,i are
buckets ,f slrup and 81 pounds OF Ih' -I ~ "1
aTI,H Vfi. Is laid on about thrce-QIuitiS OF an
intl tli,k and covered once OF tNiIt w ,7,s; 20
90, d. ..,,.l b.. mixed with h3T enough t. retain us
pl..ticity anal be laid on from about one u "H0 "NN
"a quarter inches.
Arrl1x OIL t!,SvREs oE TIE GROWTH or FLANIS'-
Mo-. Masters and Gilbert have been lnYes'i-
gatiuptlc action Of ranuIcs in fyoune the growth
oi certain s1ccic, OF plants and for tins ooJect
t,y,Ig. ,tal.cut series of meadow plants were grown
sonorqtcIy In wooden boxes, both without manure
md with five different lnanvrcS, such as manuros
furnishing rlosphates potash, &c, ammonium sai'S'
sodium nitrate. ashes and ammonia and ashes WIN
sodium nitrate The soil employed was tho.Aht 20
nave been too rich and tine results of the olsefsa-
tious of the two seasons were somewhat coO,I@luc
tory. OF the three ciovcIs ~ y0uth P'ot "H
were iD tho i.st seasons much n.Hchea ny tLe
manure. while Lotus cJrHcf'aiaS seemGd ~
iur,d Ia liz. second season the ash alone hhu niue
effect the cOycrs' out IN boi seasons ni'IC-ouous
mauuIcs. with others, produced lhc laist,' t4vl'i
With six kinds of grasses tine ash manure alone DiU
little effect; aud in almost every case the ptS'
,ro+l, ,r iron, mixture of ashes with nitrogen.
Observations on tle Development Of root induced
the opinion That those plants which sIS sse57 cheiN
under En-r. i1aGu.lae, are those whose .:tott OF
gIOWth gives tle4 'lc Wioea' LoIu CD 'I1 5oil
PErr,rR1oy or CHROME ALUr,-In the use OF
alcohol. suiphu.ous acid, OF sulpame,cd hydrogen,
AZ reducing agents, in the preparation Of chrome
alum mow so much used in photography trou
bchromate of potash and snlphuTic acid the end OF
The reaction is obscure and according to the con-
ccntraton, q greater or less elevation OF tcnpeIa-
ture occurs which requires careful attention. lest
green uqcrystalliz5ll8 solution bc formed. BY the
cmulovncnt of oVaic acid as the reducing agent
PROT .,1ecr simviins tlc process, avoids heating
in the reduction, ana an uncertainty as 40 t t4o-
titv of the reducing agent necessary without re-
curing ans special apparatus 10 make 100 parts "l
clr.1ne alum 2g5 parts Of the hchTOn2te OF potash
Is of crvstaiized uNac cId, ana 50 OF c0nccuIa'e
sulpuuric acid are weighed ont and the last Is
diluted with water 20 cause IL 70 dissolve the
bIcnroHatc. which is added 90 tne acid stlil warm
from CIu,ion. When the SOLUTION IS compete ana
The li0ud cool the ONahc acid is stirred in n small
p0rtiun-. tine evolution OF Cubohlc acld lldicaUng
The commencement ol the reaction. Cryst3ls, ol
chrome aluu separate tom The Llt-Ied hl"i1, l'lt
10 sDlufautUtls evaporation.
ProDrcuov or Con- TAR, &c.-Dr. Behrcns
rivcs I'm detail results oi experiments with refer
ence 10 the effect of temperature in gNs manuactuie
upon the tar formed. The tar from emthen retorts,
recurring higher temperature. was much richer In
beuzol and toluol tLdu that from the PauweIs
svst, f., , coke furnace and also contained large
Quantity of uaph,haiue and other solid matters
while that from the P3uwcl arrangement, with
more volatile oils. also contained a considerable
amount of substances soluble in 2llalies the car
bolic acid being little more than 9tTace. b intro
duciug stream of heavy OILS, as USED I'D pI ee4N'.-
tiOu of wood. on large scale, INTO suitable gaS
manufacturing I..ort, ."o per cent on b-nH'i allg
touol, some Nylol, and only traces Oh cuihol ana
cymoi We're obtained at a proper temperature, from
which pure benZOl was more easily prepared tAdI
from the l yht oils by using eafiueu Ictoiis. aJ
brL.T +fiu fine usral temperature, with increase OF
charge the quantity of gas was luc eaSeo ls Hu4i-
ity uu.muaircd, and the eold consuJoculs "l lNe
10 ,.lrttiuC the constituents by fractional" dstll-
laiiou, as wen as some ot their uses
DETECTION or ArsE,IcAL CoLORs ~ PAPER, &C..
IL Hager gives the following process Tor detecting
arsenical color in paper A piece Of the paper Is
soaked in concentrated solution OF nitrate OF soda
IN a mixture OF equal volumes Of alcohol and water
and allowed to dry, aud thcubuned in atat porcelain
capsule. The ashes are covered with water, several
81 1,1fio oro al ddnd eo as IN
produce a strong alkaline reaction then heated to
boiling. and filtered. Peunang3nate Of potash is
GRADUALLY added to the warmed Gltrate, previously
ncidiaed with dilute sulphuric acid as long as de-
oooraton, or conversion Of the red to yciiowiSh
brown color, takes place ard finally slight excess
of the permanCanate Is introduced. II the liquid be-
comes urbld IN the operation 10 must DC HltcItd
After cooling and addition of more dilute sulphuuc
acid. a piece of pure zinc IS added and the flask
closed with cork WITH TWO splts IN ~ III one OF
which a strip of parchment paper molstened with
nitrate of silver is fastened, and IL the other
strip mOsteued with acetate OF lead. II arsenic be
present the silver paper soon daIkens. Inc lead
paprr i simply intended TO indicate the presence OF
euiphurctted hydrogen. The treatment with the
permanganate is absolutely necessary, otherwise
ilackeniug Of the silver paper auda shght browning
0f the lead paper VIII invariably take place, though
perhaps only after some time, even IN the absence
of arsenic.
PREPARATION OF GEIATIyE-The high price Of
fine peatine induced Hewze 10 attempt the prepare
tion Of a cheaper and equally good article. he
began with a brown, almost black, glue, OF poor
quality obtained a secondary product IN the
manufacture of neats-fOOt oil, and made by digest
ing feet with steam with adhering hair, after re-
oyal Of the hoofs and leg bones under the pressure
of three atmospheres for three hours; then allow
ing the liquid to stand for half an hour, III order
that that the fat might collect on top, and next
drawing off the strongly Ianmoniacal solution OF
glue stTaiping and evapOrating in steam bath 10
"a friable black mass Attempts TO bleach tins with
eulphurous acid, and sulphite OF soda and hydro,
chlorc acid were entirely unsuccessful, and would
CATIONS Of the cause of the dark color were next