The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1900-09-08
Correspondence Baltimore County Union.
SCIENTIFIC MIS- CELLANY.


SCIENTIFIC MIS- CELLANY.
A Convenient Cement -Dryness of Houses
Animal Kinds-A Memorable Efface-
ment-Death OF City Trees-Habit in
Plants-An Intimation of Ball Light
ning-A Dose for Steel-The Modern
Way.
A much used material, known as Vinnese
metal cement, Is copper amalgam prepared IN
cipitated as a very fine powder from a solution
OF blue vitrol by means OF strips or zinc, and,
after being washed and then treated Win SO,
luton of mercurous nitrate. hot water Is poured
over this copper in a mortar. and the mercury
lin the proportion of parts to of copper is
added. The mixture is kneaded intoa very plas-
tic mass. The resulting amalgam becomes so
soft under water that it can be used for model
ing the most delicate objects from plaster casts.
it hardens into q malleable mass that can be
polished like gold and Is not readily furnished
except by hydrogen sulphide, and 1t is strong
cement OF solder for metals, the bright surfaces s
#SO to 80 Cent. When impressions have been
pade on thin sheets, the amalgam may be rein
2rced by pouring on molten type-metai.
he air of furnace-heated rooms has been
wn by Mr.. R. Dec. Ward to be drier, than
nat Of many desert regions. The mean relative
humidity of the room tested was 30 per cent
for three weeks in November, and the mean
& s y ner M tnT S ope lowest a openr
|nual mean known in the United States is ~
per cent. for Yuma, Arizona. that for Sante Fe:
% per cent, was found for five summer months
in Death Valley. Cal.
The Berlin Museum of Natural History, con-
fains 100000 animal specimens, representing
100000 species. It is estimated that total of
described, of which the insects number 100000;
birds, 1900; fishes, 1900; reptiles, $500; am
phibians. 1900; arachnoids, 10000; mollusks,
$1,000; worms. 5000.
Experiments by E. Klein indicate that, con.
ho ls cyprus ana diphtRera do not survive
than or weeks after burial In the
sara Sc ay ~ f lbs promnent
life forms. Naturaists of the nineteenth CEN
tury have had opportunity to watch the passing
I of remarkable animal in the Great AUX or
Care Fowl, which still existed in number OF
fiocks at the beginning of the century, but is now
known only from relics so priced that skeleton
has been sold for 5000, skin for $3.50 and an egg
the modern life struggle. while practically
Wfnglese and collecting together in helpless
multitudeg, 1t tempted man by the food quality
OF both flesh and eggs, and the continuance Of
the race depended upon single egg year laid
bt each female. Extinction, however. was grad
ual. Boatloads OF the eggs were collected more
than four centuries ago In Iceland and the neigh
boring islands, and the ruthless destruction OF
eggs and birds was continued irregularly by
sailors until, in 1880, the sinking of a volcanic
island buried in the sea the last important breed
ing place of the auks, and the few survivors
were left on the small Elderly Island. Here, on
June 3, 1874, three sailors captured two speci-
mems, the last Of their kind, which were stran-
gled and sold for $45,
The trees in the streets and public places of
Paris are estimated by M. Mangin to number
600 chestnuts and 1900 elms. the remainder be-
ing sycam0res. naples, lindens, ETC., with ap-
parently only one oak and one mulberry. The
mortality among these trees is great. In the
centre Of the city the trees suffer from lack of
air. In gardens surrounded by houses the refiec-
on 81 as rays tS p % G SH b
ness of the ground and especially by the salt
used on payements for dissolving snow. But the
greatest disaster is wrought, it Is believed, by
excavations of the engineer.
49,
In some interesting experiments by English
bOtanists, sleeping" plants, or those which had
taken their nocturnal position, were placed In
dark room. On sawaking'' next morning they
day. even when that position had been made
oblique by one-sided illumination.
now nearly completed after 10 years, will show
nearly 100000 stars down to 14th magnitude.
elobuIar electric discharge is produced bys.
Leduc. French electrician, by arranging two
fine polished metallic points at right angles to
p papeT. and Connecting them with an electro.
static machine. The effect is made more sure
by placing a sheet of metal under the photo
the paper. On separating the points two to
four inches, an eftuvium appears at the positive
and glObule at the negative, the gl0bule sepa-
rating itself from the point on reaching GER
tain size and travelling slowly by q more or less
irregular path to the positive point. The time
taken in the passage is one to four minutes.
AS the positive is reached, the light and the
charges disappear as If a conductor had cOnnec-
ted the machine terminals. but the phenomena
are repeated when the positive is moved to a
fresh place.
Important effects are claimed for a steel-im-
proving powder lately patented by Messrs.
Budzinskf and Schouvalotf, of Paris. The mix
ture consists approximately of $50 parts OF
backwheat meal. go of corn -four, 300 of char
coal. 10 of red pepper, and Is of asafoetida; and
the treatment is simply the plunging of the
81 until il acquires the well-known blue colorl
action reaches depth OF about s1T.n e oI
treatment. The steel is rendered so soft as TO
be easily worked, while it has greater strength
than before on hardening; 1t is given inner
grain; and over-heated steel is regenerated.
-
A French method of disposing of putrid meat
and infected animal carcasses is to place them
The heterogeneous substances are dissolved, and
the solution is drawn off from the fat and sent
TO superphosphate factory. All germs are de-
stroyed, while valuable fertilizing material is
obtained.
Corks that have been stepped In vasaline are
Sad to be an excellent substitute for glass stop
pers without their disadvantages. They are not
affected by acids or chemical fumes, and they
do not become fixed by blow or by long disuse.
Nfae Eo1Ie Exourefona