New-York tribune., 1874-03-07

Bpctod as follows: Immerse piece of white woolen
earn in the beer scdiAed with hydrochloric acid, on
q 1,ater-bath Since extractive matter will be pre-
cinitated bv picric acid and will impart dirty
brownisl yellow color TO the yarn treat the latter
with warm dilute ammonia water, which Will eX-
tract ell the picric acid filter and concentrate the
solution on a water-bath TO small volume, and add
n few drops If cyanide of potassium. The smallest
trace of picnc acid will be indicated bv a red colOIa-
lOn due to the formation of lsOpurpurate OF potaS
SUM.
AmMoNIA CHLORIDE FROM BOILING ESTABLISH
MENTs.-Terne, in Diager's P0lytechnic Journal calls
attention TO productive source of ammoniacal salts
in the refuse from the slaughter-houses Ho refers
10 the immense establishments near Chicago, where
from 5000 to $1,000 cattle sometimes butchered
in ngIe day. The refuse. and the useless flesh,
are placed in a large iron boiler, and boiled undor
pressure of three or four atmospheies The lat rises
10 the top aud beneath is a liquid which might be
considered solution of glue had not the continued
boiling under pressure completely dcStroyeu ltS
binding power. These tank waters, although use
less for the manufacture of glues are suggested by
Terne rs capable of beng prOttabiy uthiIeu since
each quart can be made to furnish from 90 10 4UO
grains of chloride OF ammonia.
ANIIaNE GREEN ON Notwithstanding to Lauth,
the wool is first to be prepared in bath to which
hyposulphite of soda and an acid, or acid salt,
lave bsen added; the sulphur preciptated on the
tendency of the wool to lose it's elasticity, and to
become soft and shrink. on account of the penetra
ton of the sulphur into the fbers may be remedicd
by adding a small quantity OF alum OF OF zane saIt
To the hath. Before treatmeDt with tho hyposul-
phte the wool must be secured and freed 10y means
of dilute hydrochloric acid from any metallic COM
pounds chat NAV have been taken up IN spinning or
weaving otherwise brown specks OF metallic SUI
phdes may be formed The dyeing Is accomplished
by simply placing it, when we'll washed, IN sol-
tiOn Of aniiuc green IN warm water ana gtadually
raising the temperature 10 ~.
Tm BEST INsEcuCIDEs.-The injuries caused by
insects 10 certain crops in many only to be
prevented by the use of pOsons; and it is matter
of much importance to select those which shall be
most efficient, while at the same time, least likely
by their color and character TO involve danger IN
their use The prevention of the ravages of the Col
orado potato beetle, which have been so serious
within the last two years can it is said, only be
complishcd by the application of Paris green or
Scheeles green an arsenie of copper; and the prac-
teal success of this treatment has induced the United
States Agricultural Department to invite expert
ments as to its effect upon the cotton worm 1t is
estimated that loss of not less than quarter to
half million bales of cotton takes place annually
from this alone, which at SlOO per BALE would
amount to from S25,OOO,09O to %oO.OJO,OOO. go
circular has accordingly been transmitted by
the Department to rs correspondents III cotton
growing countries; and the monthly report OF the
Department for November, contains digest o. the
replies TO the queries contained therein 1he gen
eFal conclusions at which the Department arrives
are that the Of one part of Paris green pure and
unadulterated mixed thoroughly with % 80 parts
of flour damaged -four being good enough answers
perfectly we'll and has proved of such utility as IN
many cases to have saved tho crops
Paris green or arsenic, mixed with water, and
sprnkled over the plants, has also been used with
satisfactory effect. The latter application should be
made moist and before using the former, II is de-
srable that the plants be wetted by rain or arti-
Cialy, in order TO tho dust to adhere TO the
leaves. The poiSons should be applied on the first
appearance Of the caterpilars and also as soon as
possible after the second crop OF worms Is seen.
Caution must be exercised to be on the wlndwaTd
side Of the plant when dusting the poison upon 1t,
and not to permit cattle to feed on the foliage.
Large hocks of turkeys have been found very
efficient III destroying the worms both IN the case OF
cotton ana tobacco.
RAINFALL AND FORESTS IN THE WEST INDIES
Mr. f. Hubbard. in some remarks on the relation of
aina and forests in the West India Islands states
that the dimlnution of rainfall in the Island of
Santa Cruz is noticeable and that in the past twenty
seven years the effect is percepibe in the gradual
change from fertility to baTrenness. Every planta
tion newly swallowed up by the onward march of
desOation augments the cause and renders the
errest Of the evil more aud more hopeless The
ment is from the East and towards the West, every
few years an estate. formerly with cane fields.
being abandoned to the graziers, whose cattle, how
ever, find meager pasture upon 1T for only a few
seasOne longer. There are streams upon the
island with the exception of a few rlls, and the
wells arc falling. Cultivation is impossible without
constant irrigation, and no means remain to sustain
Iifo planter not long since set out few trees
upon his estate and lost every The Island of St.
Thomas is similarly affected, though being lotier.
il to have rather more rain. la the island of
Porto Rico. which is almost wholly mountainous |
the rainfall still continues abundant, and the flora
does not appear to have suffered. The sad change
which has befallen the smaller islands is without
any doubt to be ascribed to human agency alOne-t0
the removal of the trees the present evil Is at
tubuted. The rainy seasons in these climates are
not continuous cloudy days, but succession of |
sudden showers, with the sun shining hot In the |
intervals and the opening of the soil TO the vertically
heat of The sun its rapid drying and prevents
the rain from sinking to the roots of the plants An
equally marked example of this result is seen in the
small island of CuracOa, which in lS45 almost
perfect desert, while, according TO history, il
once garden of fertility; the cause being the cut
ting down of the trees for the export of their valua
BILE timber Almost within sight of Curacao is the
coast of the Spanish Main, covered with the Tankest
vegetation. over which the burdened clouds shower
down abundant rain, while at Curacao 'resh water
is among the luxuIies.
AN EXPERIMENT IN SOCIOLOGY.-It is interesting
TO place on record the success of recent experiment
of what may be called practical sociology, as illus
trated in the experience of association of Friends
formed in Baltimore shortly after the close of the
war for the purpose Of advising and assisting i'm
poyerished Friends in the Southern States The
immediate object was to afford physical relief
but as the continuance of physical want can only be
prevented by removing the cause, the association
wisely connected with their benefcence system of
mental moral and religious education. Their par
tcular field of operations in the rural districts
of western North Carolina In 1867 the association
purchased farm of 200 acres at Springfield, be-
tween Randolph and Guilford Counties, on which |
ola fbair int