New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1873-09-20
APPLIED SCIENCE.

ACTION OF WATER ON LEAD PIPEs-Sir hoper'
Christison who has devoted much attention I" 'ne
Influence Of water upon lead in passing through
pipes &C. has ascertainod that the purest waters
are those which act most powerfully upon lead cor
roding IT, and forming earbOnate OF Pecullar ana
uniform composition, and that an salts lmPeee tlls
action many preventing t altogether some OF them
doing so when in extremely minute proportions.
IMPROVED METHOD or DRYING CLOTH FABEIcs.-
An improved method of drying cloth textures de
vised by Bastaert, and one that probably may be
applied advantageously alarge scale in the laun-
dry consists in passing them over several rows OF
apertures in iron pipes,'out of which superheated
steam issues This penetrates the cloth and dries IL
In virtue of the tendency of the steam 10 ABSORB
water and its high temperature. Inc steam ans ~
drawn into hue above, in which there Is a strong
current of air One advantage of the process IS that
the original surface of the web not exposed 10 tn
injury it is apt to sustain rom contaS' WIN
drums or plates in the ordinary process
GUAIMATE or IRON PHOTOGRAPHIC FAPEh-I"'
British Journal Of Photography announces rci',"'A
able compound of gummc acid ana sesq'H-oAuo Va
iron which renders paper coated with IL SeuslNo "
GoL+ To prenare il we are directed to add ammo
mia carbonate carefully and with continual surfing
N n solution of sesquchlOride OF iron, until the
nixt,re eaervesces violently. Filter the liquid,
saturate the paper with It, dry IN the dark, ana then
cover IL with a toleTably thick him OF gum araDc,
and LAYER OF guiluliS OF liuh VIII
form upon IT, PAPER thus prepared does not become
deep yellow for some time, aud, ii perfectly airy,
remains very flexible for long period ana retans
fine gloss.
QUICK-DRYING On. Colon AND VARNIsH.-Accord-
ing 10 the MustG-Zeung the following affords an
excellent yarnish, imparting a beautiful and dur
able gloss which is protection from the action OF
moisture and of the atmosphere and also causes OIL
colors to dry more quickly. Heat II parts oil smell
lac and four parts of borax, under constant stirring
in copper kettle with 80 TO 100 parts water, until
n uniform mass results Then cover the kettle WELL
and after cooling, pour the liquid into bottles which
are 10 be well corked. Its color depends on the use
of bleached or unbleached sheac To impaTt the
property of drying quickly oil cOlos for printing
or painting mix equal weight of the shellac So
luton with the color, rubbed up tmckly, using
beached shellac with light colOrs. To prevent too
rapid drying IN printing some husGedcon VaInii sh
should be added, but for painting oil of turpentine
will answer Care must be taken TO have a per
fectly uniform mixture with the cOlOring matter;
and only to prepare as much OF u as may be needed
at time as it viii become worthless by hardening
while the sheac solution can be preserved lndeh-
ntely. in tightly cOrked bottles l{y mixing the !
varnlsh with yellow ochre, an excellent pant Tor
floors may be made the brilllancy OF which VIII We
heightened by coating the floor, after dryin2, with
the simple Vauish. The drying of other slow var |
nshes be FASTENED by mixing this shell@c Irepa
ration with them as needed.
tinglished pbysiologist Brtcb.e has been making !
some Investigations upon the substances producedn
the digestion Of the non-nitrogenous constituents
of food ordinarily called carbohydrates. He dis |
tnguishcs in the first place. between the dextIin |
which is coored red by iodine and that which is not
colored at all by this reagent calling the former
erythrodextriD and the latter achrOdextrin. Com
Inercial dextrn, made by roasting raw starch, is |
mixture of erythrodextrin and soluble starch or
amiduln. That made by Payens method-in which |
the starch is moistened with nitric acid, dried and
Toasted-contans beside eryhrodeXtrin, both achrO-
dextrin and sugar. Starch treated with sulphuric
acid yields first amduln. then erythrodextrin, then
achrOdeXtIin aud sugar. The process OF mating |
produces achrOdeXtrin In quantity. When now, the
contents of the stOmachs OF dogs killed from one TO
five hours after meal made up mostly OF starch |
were anavZed, large quantities of soluble starch and
al eTythrOdeXtrin were found while achrodextun |
and sugar existed only IN traces; III the small mites
tine. the other hand, there no ythrOdeXtrn.
but sugar always present. The small amount OF |
sugar In the stomach ascrbed TO the checking in
fuence of the acid of the gastric juice upon the |
saliva the action of this very acid producing, how
ever bc soluble starch present while the conoined
successive action Of the saliva and the acid, pro |
duoes part of the erythrOdeXtTln. The ct1ef part
Of this substance Bricke bias proved is due TO the
Tactic acid fermentation. which he thinks Is nor
mal digestive process intended tOpTepare the starch
for more rapid transformation into sugar In the |
duodeuum, under the influence Of the panCreatic |
Juice.
INFLUENCE OF FORESTS on THE TEMPERATURE |
OF TIE GROUND-The Bavarian physicist Eber-
mayer has investigated the influence of forests Oh
the climate of the neighborhoOd shown by the |
numerous observations recorded in that kingdom.
Among his conclusions are the following results as
90 the temperature of the ground, determined by |
thermometers sunk TO depths of one and six inches
and Of one two three and four feet. For the upper
layer Of EARTH within one foot of the surface the
minimum monthly mean temperatures occur both |
in open and in wooded regions in the month of |
lowest temperature occur in February. The tenn
perature increases from February on until its max
imum IN July; at the high stations only does the |
maximum occur in August. From July or August |
the temperature decreases TO January February.
10 the agricultural interests II is especially import
ant to note that the monthly increase of tempera-
tuTe is most rapid in MAY, and is nearly great III
April il is least IN June and July. Concerning the
strata lower than foot Ebermayer finds that the
monthly increase in temperature is greater in June
and July than IL is in the upper stratum. The loss |
of temperature Is IN the upper stratum, most rapid
in November and October, and least in the coolest
weather in January and February In forest
places the lowest temperature occurs in February |
and continues TO June during which interval the |
ground il cooler than the air in July and August |
the ground is somewhat warmer than the air. The |
greatest difference between the temperature OF free
and forest land in May and the least in June.
The fluctuations IN forest land are less than in open
ground. The influence of the forest IN preventing |
the cooling of the ground by the radiation Of its
heat If most noticeable in October and November |
and least in January and February.
NEW Form OF EYPLoSIVFs.-Sir Charles W Vim |