New-York tribune., 1874-06-13

from the start large and continually increas-
ing success During the two first years it has
regularly gathered material from over 90 periodi-
Gals. some English and French, but mostly German.
1t has published about 600 abstracts of reports of
scientific investigations and 200 shorter notices.
The subjects treated are grouped under the
following heads Atmosphere and Water; The
Soil: Manuriug; Animal Productions Vegetable
Production; Agricultural Technology; Fermenta-
ton, Decomposition, and Decay-the last subject
having chiefly to do with the manufacture OF
fernented liquors Many of these Investigations
are of great interest and value Such are: Studies
upon the chemical processes that on IN the SOIL;
the effects of different fertilzing substances upon
the plant growth, and of different methods of fod
dering upon the growth of cattle the production on
milk &c. Ii is an encouraging fact to the friends
of agricultural science at home that literature OF
this KIND should be well appreciated, even II 1t be
IN foreign country
DEVELOPING CRYSTALLINE STRUCTURE OF TIN
Fou--The development of the crystalline struc-
ture of the of timed iron for purposes of orna-
mentation, has been known for long time con-
ssting essentially of the application of slight acid
TO the exterior. Tin foil also be made TO ex-
hibit the same appearance and in a still more char
acterstc manner; brt the secret by which this was
accomplished has until quite recently been well
kept The process according to The English Mechanic,
is as follows:
A perfectly plain and polished east-iron plate is
heated by number Of small gas Jets beneath, TO
temperature Of about 400 just short of the melting
point of tin and the gas regulated as uniformly
to maintain this temperature. sheet of tin foil is
laid this plate and to bring ii in perfect contact
Herewith roller made of felt or soft cloth sim
liar 10 printers mixing roller is passed over the
foil. which at this high heat loses elasticity and
touches the plate all over The next step is to fuse
the TIN foil To effect this Of little gas jets is
+n1 -tfrfao nf tha foil lxxffh
small crcing movement this in its passage, COM
pletey fuses the tin which quickly congeals again,
and NAV be at once raised and the operation repeated
on another sheet. The movable of gas jets is
simply a small tube perforated with a line of fine
holes and attached to length of flexible tube con-
veying the gas thus allowing movement every way.
II is scarcely necessary TO state tbat, the fo Is
not in close contact with the hot plate at any part,
a hole is sure TO appear. This cannot possibly
occur where the foil is held together by every paTt-
Gle resting the bed.
The fois now only require to have the crystalline
pattern developed This is done by immerslng them
for q few minutes IN . mixture OF equal parts OF
nitric and hydTochloTe acids dilnted with hve parts
| of water. As the crystals appear perfect,
the foils are thoroughly washed, as to remove
all traces of acid and then coated with hard, trans
parent vaTnish, which may be colOred blue, red,
yellow &c. according 10 fancy. These coors must,
of course be transparent pigments such as are we'll
known 10 the yarllsh manufacturers,
Pollution OF RIVERS BY MANUFACTURES AND
CITY SEwAGE.-The great attention recently given
10 these of disease and discomfort by various
European Governments seems more than justified
according TO exhaustive summary, by Fischer OF
the results of these Investigations Thus, the refuse
water of almost all industrial establishments con-
tains more less matter in solution, suspension,
calculated TO render it unwholesome and unfit for
MANY purposes. The nitrogenous organic material,
however seems specially Objectionable Tanneries
contribute so much of this that their inteIdictiOn
near large cities is suggested Paper mills, in the
washngs of the rags and of the espartO grass, also
furnish a liquid very prone TO putrefaction. The
refuse water of sugar manufactures, beside being
very rich IN nitrogen, readily passes into putretac-
tion by reason OF its comparatively high tempera-
ture so that streams are covered with scum from it
for miles and the fish exterminated The waters
from manufactures of starch and spiituOus liquors
have similar properties Washing, bleaching, dye
ing and printing processes generally, add refuse
rich in organic matter TO water; that from woolen
and carpet manufactures being much more impure
and that from silk much less impure than that from
cotton factories. To the preceding may be
added manufactures OF chemical products
and dyestufis generally, and fat-extract-
ing establishments, while soap-boiling seems
10 be but slightly Objectionable in this
respect Numerous plans for utilizing refuse of this
character from different sources and thus prevent
Id pollution of the rivers by it, have been suggest
ed. But beside organic matter arsenic Is frequent
lv met with and sometimes not in trltiing quanti-
hes. especiallv in the water from soda manufac-
tories on account of its frequent presence as an i'm
purity in the sulphurc acid employed; and for the
same reason in part It is also found IN water from
dveing establishments. well in part also on ac
count of the employment OF arseniate of soda with
madder coors. In wOOlen factories the soda and
soap used add arsenic TO the other communicating
matter: and generally whenever large quantities OF
sulphuric acid are employed, perceptible traces OF
arsenic may be found il also occurs in the refuse of
aniIine manufactures. Free hydrochloric acid is
added in large quantities by soda-works. and chlo-
rldes from bleaching establishments while sulphur
eted hydrogen a1d, ultimately, free sulphur, are
frequently liberated from soda reslCues by the ac-
ton of the acid waters
The sewage of cities however. with Its accumula-
tons of domestic refuse. of rain-water washings
from the streets. and eXcrementiaous matter con-
tributes the largest share 10 The sum total OF putres
| cible nltTogenOus refuse aItholeh lie hIthness
NAV al times be masked by the refuse products nom
manufactures while the organic contents are not
rapidly destroyed, as Is supposed, by mlXlDg With
twenty times the quantity of river water. The
remedies suggested, In connection with the various
/ species of impurities almost without number,
prevention principally by the separate removal and
utilization of the solid portion, being the first 10
| suggest itself lhls does not seem, however, 10
! meet the and, consequently, purlncatlOn OF
| the polluted water must he resorted TO- either by
means of chemical reagents or OF hltratOn, or OF
/ some method Of upgatlon wltl tue water. win
! this In view many chemica. reagents have been
! perimented with and numerous combinations have
1 heen patented lime, salts OF aluInina and iron
| carbon. ana clay entering most frequently INTO
! the processes. Filtration. downward and upward
through sand. &e. haS also teen extensively tried
bat none Of these afford satisfactory results far
at least n dissolved organic matter is concerDed
moi even half of IL being eliminated by any OF the
| chemical methods The purified water has fire.
quently been found de veOp animal life cOpiously.
! By intermittent downward filtration. through
| hnv he heir n
| idle from six twelve hours. and thus being
III abs he organic matter