Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1882-05-23
SOME SCIENTIFIC MEMORANDA:

1t is reported that Professor ]. Lawrence
Smith, of Louisville, KY, lately discov-
cred in native iron which was found in
1875 IN the Province of st. Catarina, Bra.
I'll, the singular physical property that in
its natural condition it is very feebly at
tracted by the magnet, but if fragment is
heated to redness and then cooled there is
manifested magnetic property with the
usual intensity of iron.
The British postal telegraph system
seems to be making very satisfactory pro.
gress. When private companies owned the
wires the best years work ever they per.
formed did not exceed 6, 900, 900 kilograms.
Last year the Postofiiee forwarded 81 ,OO0..
600 kilograms. Fifty thousand miles of
wire in 1870 had increased to more than
100, 900 miles in 1882; 1900 instruments
worked by all the compani es had increased
to nearly 5000 worked by the Postoffice.
and ., 500 telegraph offices under the old
regime had increased to more than 5000
under the new. Such are few of the in.
teresting facts taken from lecture by r.
W. Johnston, which has just been pub
lished.
DR.. P. Ebell, of Hanover, draws atten.
tion to the use OF peroxide of hydrogen in
dentistry. Sauer made successful expert.
ments with it in bleaching discolored and
carlous teeth. In cases where the teeth
are colored with matter such as Lichen
dentalis, ETC., he uses peroxide of hydrogen
in conjunction with finely levigated
pumice-stone as means of cleaning in
place OF water. Teeth, the native elements
of which were filled with colored matter,
become somewhat paler after several appli.
cations A suitable liquid for cleaning
teeth and mouth is prepared by mixing one
part of three per cent. of peroxide of nv.
drogen with ten parts of water. In case
of carious teeth the peroxide of hydrogen,
locally applied with wadding, gave good
results.
The Saturday Engineer makes ssronR
protest against the reckless waste of the
water supply of all our cities. 1t SAYS;
Z" The repression of waste is not stintinn the
use of water. 1t is simply the stopping of
leaks and the checking of carelessness.
The way to stop the waste which does in.
jury to city is to make the consumer re.
spousible for the tightness of the plumbing
on his premises and the closing of his fau.
Gets when water is not being used. The
amount of water he may use is not what
affects the public; it is what he throws
away. In 1881 New York consumers
paid into the city treasury 81, 500, 600. In
addition to that the taxpayers paid for the
water supply sl,ll7, 500. This was the
amount which property contributed by di.
rect tax to the maintenance of the water
supply. Why does property have to nav
this enormous taxi"
Pattison Muir gives this method for de-.
tecting tin in the presence of antimopy. II
is based on the fact that stannic chloride is
reduced to stannous chloride by BOILING
with metallic copper. The precipitate6
sulphides OF the arsenic group are warmed
with concentrated hydrochloric acid. The
insoluble portion is washed and tested
for arsenic by Bunsen's film test. The 40.
luton is somewhat diluted about three.
fourths OF it is boiled for at least ten min.
utes with copper turnings (which must of
course, be free from TIM, poured off from
the copper, and tested, for stannous chic.
ride by adding mercuric chloride. The re.
naming smaller portion of the solution in
poured on to plate of platinum, sur
rounded by piece OF zinc.foil. II the
platinum becomes covered with a black de.
posit 1t IS removed and examined in the or.
dinary way.
Paul w. Hasluck, in a paper on the art
OF turning, says that an attempt to trace
its progress would not only be wearisome.
but very speculative, as there are few in.
disputable data on which to base a con.
nected history. But the rude appliances of
thepaststand outin striking contrast to these
OF the present. Long before the fywheeI
worked by a crank was invented or used
lathes were driven by the aid of spring
pole, and also by bows quite differsnt
from the modern drill bow. Now turnery-
both the art itself as well as the objects
produced-has been SO perfected that it
seems difficult to limit the range of its an
plication. The lathe is itself production
of former lathe. As skill has increased. 80
have the productions of the lathe in.
creased IN perfection. Thecenter lathe gave
the means of making the mandrel lathe, and
the latter gave birth to the screw.cuttinp
lathe /; and so on through all the innumer
able varieties of the tool now in EVERYDAY
use. If lathes larger than the largest now
used are wanted, they can be made ON the
machines now available. If mechanism ia
to be refined TO a greater perfection than
now exists, the tools to do it can be made
on the lathes we now possess.