New-York tribune., 1874-10-26
APPLIED SCIENCE.


REMOVAL OF Day PUTTY.-According to an En-
rhsh journal, the difficulty of removing haru pu'"
hom window sash can be obviated witn eies' ioa
uess by simply applying piece OF hea'ou Ao''.'
such as a soldering-iron or other similar 'np''~ ~
assaa slowly over the putty thereby rendering tne
Htter so soft that il win part frem the wood WIN
cut any trouble
S,rr HYDROGEN GENERAToRs.-Dr. Fresenius'
v;tb view 70 avoid the dangers OF explosions IN
hydrogen generators, which, as every cnems'
Knows are of frequent occurrence despite the exer
.se of both patience and care has applied thereto
the principle of the Davy safety lamp. Anumber OF
discs of fine wire gauze are placed in short glass
tube and held in position by cotton WOOL presseu
AGAINST them on both sides This little TUBE is III
troduced near the exit of the gas, and prevents eS
explosion from extending to the WASH po''io anu
generator itself.
CuRr FOR DrPurHERIA.-The ravaRes OF diphtherla
m Australia have been extensive within the last
Sew years that the Governments offered large re-
ward for any certain method of cure and among
other responses to this was one by MIR. Greatheao
who at first kept his method secret but afterwards
communicated it freely to the public. 1t is simply
the use of suphuric acid, of which four drops are
diluted in ee-fourths of tumbler of water to be
administered to a grown person and smaller dose
20 children at intervals not specified ne result 10
said to be acoaguaton of the dlphthentic
and it's ready removal by coughing. III Is assertt9
that where the case thus treated has not advance9
70 nearly fatal termination the patient reco'eroo
m almost every instance.
FOOTPRINTS IN SOLID RoCK.-Considerable inter-
est has from time to time been excited by an
nouncements of the discovery OF supposed human
foot marks in the solid rock the latest being an ac-
count in The Nashville Union of August 2, of their
occurrence at the of Harpeth. ltmay not be
amiss to state here that there can be no question OF
the artificial gin of all these marks, the simntude
of the human foot being favorite form OF picture
writing among the aborignes. Several well exc
cuted specimens are in the National Museum at
Washington; and others are TO be found elsewhere.
They are usually executed IN limestone, slate, OF
sandstone, and are of very rude workmansnip, nol-
wthstandlDg all encOnums upon their mar Veious
perfection On close examination they VIII be found
cut through the laminatiOn of the rock, instead OF
mdentng it, as would be the case II produced oy
naked foot trayersng surface In plastic cOhultion
EUROPEAN sAvANs IN AMERICAN INSTITUTIONS
Prof Proctor writes to The academy in reference
10 the policy of the importation by America OF III.
ropeaD savans professors In colleges directors VI
observatOres &c. and remarks that at all the chlel
centers OF scientific culture, whether In New-En-
Gland. the Middle or Western States, he found the
general sentiment favorable to such action. He
however, states that while at the college of his
~
and is regarded with special PRIDE. was the case
with Agassiz, elsewhere he is looked upon with
jealousy especially among those best able to weigh
the merits of American science. He thinks that 1t
is only among the less well Uniformed Americans tnat
the qualities of the American leaders In sclentlnc
research are undervalued. and this merely because
shortcomings are imagined which have no real eX-
istenee. He remarks that the Amerlcans, VINO are
best able TO Judge know that the eabOrateness OF
European scientific training is less effective than
their own more practical system; and they consider
ii unfair that the claims of their best men should
be overlooked i'll favor of strangers.
ARTIFICIAL CoLoRATION OF METALs.-A method
for giving various tints to metals has lately been de-
vised and consists in coating their surfaces with
thin film of sulphde. Ii is said that in few min
utes articles of brass may be coated of any color,
varying from gold to copper-red, then to carmne,
dark red and through the several shades of blue,
according to the thickness of the coating employed
The coors said to possess good usteT and If the
articles to be coated have previously been well
cleaned the coating will adhere with sufficient firm
ness to admit of polishing. The colorng solution Is
prepared as follows: Dissolve +. o. of hyposulpbte
of soda in pound of water and add or of acetate
of lead dissolved in pound of water. If this clear
solution is heated to say 2OOo Fahr. it decompOses
slowly and precpitates suphide of lead, III metal
lie surface is present portion OF the sulphlde Is de
posted thereon. aud according to the thickness OF
this deposition its color will vary as above de-
scribed. Treated in this way iron takes steel.6lne
color and zi4e brown, WGsre splphurc aGld Is Is
snbstltuted Tor the acetate o. iea9s % Didso VII oo
coated with a beautiful red which Is ,"uVNSV ,py
Green and finally by a brown with green ana red
iridiscent glitter Seyerai appIlcatlons VI .nio
useful discovery will doubtless, suggest themselves