The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1900-09-29
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.

An Unsafe Material-Living Pictures-A
Rat Destroyer for Ships-Trillot's Color
Photography "A Mysterious Light
Motions Of Growing Seeds-Green Wis
ion-Non-Drying Oils Myth-An In
sidious Poison.
The dangerous character of wood alcohol
seems to be little understood. but has been en-
phasized within recent months by a number of
painful experiences Not only have small doses
Of the commercial spirit resulted in death but
from two to five teaspoonfuls have produced
total blindness through atrophy of the optic
nerve. Even initiation of the vapor has caused
serious impairment of vision. The poisonous
effects do not depend on impurities, as is proven
By the reported case Of young man convalesc-
ing from measles, who surreptitiously drank
four ounces Of highly purified wood alcohol,
and after recovery from the intoxication re-
manned so nearly blind that he could barely dis
tinguish light and shadow.
"a
Attempts to make "living pictures" have
been traced backward about twenty centuries
in recent book by H. ". Hopwood. AS early
as 1861 a British patent was issued for the max
ing of instantaneous pictures of moving objects
and from that time to 1896 there were patented
80 other inventions. In the next two years not
less than LOG inventions were patented. The
satisfactory work of reproducing the figures in
motion belongs to the latter period. yet the
century closes with this art in highly perfected
stage.
The discovery of many dead rats around some
casks of fermenting molasses has given French
genius a novel idea. He suggests that rats on
shipboard may be destroyed by filling the bilges
with carbonic acid gas from cylinders of the
al f1s,f1 Nd ofrku ont hat
phyxiating gas has no warning odor, while it is
harmless to ship and cargo.
The surveys for the Transcaucasian railway
we're made by the Photographic method, and,
while the cost proved to be only third as great
as the usual survey, much time also was saved
-.
The image on an ordinary Photographic plate
is q precipitate of amorphous silver, and NJ
&c change thss silver Asto
thin superposed laminae,- with the idea that
color effects would then result from the phe-
nomenon of interference. He has effected the
change by exposing the plate to niric acid vapor
until all trace of the image disappears, then ex-
posing to moist hydrogen sulphide until the
image is again brought out properly. The sill
yer is thus converted to a Illuminated condition,
and by reflected light the image shows strong
no definite relation to natural colors. Yet it is
possible SO to localize certain colors as to give
an approach to those of the objects represented.
In the experiments already made. M. Trilot
has localized green, red and white upon the
proper parts of an image showing foliage, red
tiled roof and white walls. and he looks for con-
siderably greater success with this system Of
photographing colors.
A curious gnis fatuus seems to have appeared
suddenly about twenty years ago nee- Berben-
ma, in the italian Alps, and to have been seen
almost nightly since. DR.. A. Battandier de-
scribes It as q flame, usually white but some
times colored, sometimes single and occasional
ly multiple. 1t moves at varying heights up to
Is feet, sometimes advancing by leaps, often
stopping abruptly. sometimes disappearing, then
lighting up the country for long distance. Its
nightly visitations may last several hours. 1t
fees from man, but is not affected by wind. rain
or snow. Carlo Fabiani, a late investigator, finds
that four explanations have been given. The in
habitants see in the flames the visible souls of
the departed others assert that the peasants are
together victims of hallucination third theory
Is that the phenomenon is q "Will-o'-the-Wisp,"
due to marsh-gas. and the last view is that it is
due to "St Elmo's fire" or electrical brush-dis-
charge. While the third theory is possible an
objection is the regularity of the apparition and
it's sudden advent twenty years ago.
-
The first bubonic plague of which we have
authentic record is placed by two physicians of
New South Wales in the year 1141 b. O., or more
than eight centuries earlier than the date usual
" assigned It is concluded that the epidemic
described in the First Book of Samuel was true
bubonic plague.
Waste gas from European blast-furnaces now
operates "A engines. with total horse power of
S7,72O.
In his studies of slow motions. Prof. Chas. S.
Slichter, by means of kaleidoscope pictures, has
so magnined the motions that the growth of
seeding peas and beans during three weeks is
shown in few seconds. The plants were pho
tographed on the kaleidoscope film by artificial
light at intervals of few minutes to few
hours during the three weeks. On projecting
the pictures upon the screen at the usual rate,'
the motion of growth was magnifed about 5OO-
600 times and the different rates of develop
ment of the various parts were brought out
very clearly. Among the striking results was
the curious behavior of a pea struggling to
enter impenetrable soil, the root curving and
writhing much like an anglo worm. while the
pea was rolled about very grotesquely.
A~s
A case of green vision, everything seen APP
pearing to be green in color, has been brought
before the British Ophthalmological Society by
II. w. Dodd, AID records have been found of
thirteen other cases. The condition was not one
pecuIisr to age or sex, and it was not due to
errors of refraction. It's existence docs not APP
near to have been explained. In at least seven
of the cases the general health was noticeably
impaired. and in ten of the patients there were
eve defects-mostly connected with the optic
nerve and retina.
The distinction of drying and non drying oils
is found by A. Livache to hold good only at mod
crate temperatures. At 1899 to 16)o c. all fatty
substances, both vegetable and animal. absorb
oxygen and "dry," the process being slow or
rapid according to temperature and previous
treatment. The final product is in all cases
transparent, elastic solid, similar to that known
from the hardening of the so-called drying oils.
ga
Lead poisoning may be more common than is
supposed. So thinks French physician, who
was puzzled by the collie and constipation of
boy of twelve until the father appeared with
the same trouble, when it was discovered that
the family had been using kindling wood from
q white lead factory. A case in young woman
was traced to the sheet lead wrapper OF her
snuff. Another case showed typical symptoms
but the source of the poison could not be de-
tected.
EssIE-"Your Aunt Mary's awful fat, amt