The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1869-12-25
SCIENTIFIC.

FAINT FOR lR0N.-A VaTnlSh for IRON
work can be made as follows: Obtain some
good clean gas tar, and boil for four or five
hours, until it runs as fine as water; then
add one pint Of turpentine to a gallon Of
tar. and boil another half hour. Apply
hot.
THB following is German recipe for coat
ing wood with substance as hard as stone !;
40 parts of chalk, so of resin, and 4 of lin
seed oil melted together To this should
Be- added one part Of oxide of copper, and
afterwards one part Of sulphuric acid. This
last ingredient must be added carefully.
The mixture, while hot, should be applied
with brush
EXPERIMENTS made by an English chem
lst, some years ago, show how much food
oe different kinds it takes to make pound
Of flesh. According to his conclusions il
requires, Of milk, 20 lbs; turnips, 100; po-
tatoes, so; carrots. so; oatmeal, 9; barley
meal, y; peas, 81; beans, 81.
A CORRESPONDENT of the Mechanics
Magazine states that the Moncrieff system
Of mounting artillery, which has lately at
tracted SO much attention abroad, was anti
cipated 1911, BY French officer, who pub
lished a system Of mounting guns not es-
sentially different from that of Captain
Moncrieff
AN ODD GUN BARREL.-A Mr.. e T.
Hughes, Of London, has recently patented
an alleged Improvement in firearms which
is something Of curiosity as well as a no
velty in its way. The invention consists in
the construction Of gun barrels with com
pound bore, consisting of three sections, one
Of which, at the breech band, is a perfectly
smooth bore; another section at the muzzle,
and l. a rifle bore (the calibre of this section
should be Just the depth Of the riflng small
er than the smooth bore secttion); the third
and middle section consists of tapering
bore, which, at each end comedies with the
bore with which it is connected. The rifling
is continued through the middle section to
l. same depth as the midd'e section, and
should be gaining twist.
DR.. LrvINGsToNE's last African dis
covery is tribe that lives altogether in un-
derground houses. Some excavations are
said to he thirty miles long, and have
running rills in them A whole district can
stand a siege in them. The writings"
therein, he has been told by some Of the
people, are on wings Of animals, and not
letters. They are said to be very dark,
well made. Geographers and ethnologists
will look with impatient interest for further
Information cOncernining this remarkable
people.
CoPPERsMIrns AND CHoLERA-A fort
night ago we published a. paper by Or.
Burg, Of Paris, showing the immunity from
cholera which coppersmiths and others work
ing with alloys Of copper enjoy. We have
now a statement BY DR.. Clapton, Of st.
Thomas's Hospital, that the same fact is OBJ
servable In London1 sHe.ias found hv in
quiries at various works that copper work
men have been free from cholera and
diarrhe, although their neighborhOod suffer
ell seere ly during the great epidemics.
This Is a remarkable fact, deserving the
serious attention Of medical authorities. Or.
Clapton's observations have extended be-
yond those of DR.. Burg. He has been able
to prove that by haudling copper some ab-
sorption Of the metal into the system does
take place. CopPer-workers get
green stains on the gums Immediately above
the teeth, just as painters and leadwOrkers
get dark, almost black line. They have
a bluish-green perspiration, aud if afflicted
with ulcers, the exuding matter is Of a
greenish color. But their occupation, un-
like that Of painters and water-gilders and
others, seem to bling them to no specific
hisnnsn