The daily Cairo bulletin., 1884-10-22
Scientific Miscellany.

Recent discussions by English au-
thorlies show that doctors are far from
agreement concerning the distance to
which smallpox germs may be convey
ed by the air. DR.. Bingham has sup
posed that infection could not be CIV
en- at a greater distance than two or
three feet in outdoor air; DR.. Hill has
placed the limit at five or six feet; DIR,
latham, at six to eight feet; and Dr.
Grieve at eight to ten feet Others
have given fifteen, thirty, fifty, seventy.
100, $50, 800 and 500 feet as the prob
able width Of the dangerous zone around
smallpox hospitals. Sir VIM, Jenner
has insisted that it is half mile, and
several eminent physicians have favor
cd the theory that infection may bo
disseminated to distance of 1000 or
5000 feet. Sir j. X. Bennett has thought
it probable that infection, like small
shot or smoke, might travel mile or
two. and that it is very possible that
mall-pox poison might strike a per-
son at distance of fifty miles from its
starting point. Reviewing the evidence
thus far presented on the subject, DR..
L. Wilson concludes that Is not proven
that smallpox infection in an active
state is ever disseminated in the open
air as far as 200 or even $50 feet.
Prof. c. Niche Smith remarks that
green color of the sun, though un-
common, is of much less rare occurrence
than is generally supposed, as he has
several times observed it since 1t at
tracted so much attention in India in
September, 1868. He is disposed to
ascribe the phenomenon to an abnorm-
ally thick stratum of transparent water
vapor, and not TO volcanic dust. Its
rareity may be due, he suggests, to the
fact that the water-vapor, when pres
ent in sufficient quantity to produce
the appearance, is usually partially
precipitated, forming clouds. An un-
usual electric state may possibly at
times give the air great clearness when
highly charged with vapor. Prof.
Smith points out that the air might
hold enough volcanic dust to produce
the sunset glows which followed the
green sun of India, and still have its
transparency unaffected and cause no
change in the suns appearance.
The mongoose, which was some years
ago brought from India to stop the
ravages of the sugar-cane rot in Ja-
maica, has increased in that island to
such an extent, and has become so des-
tructive to poultry and even to fruit
and vegetables, that it seems liable to
soon become veritable pest. Since
being introduced from Europe, the dog
has become very numerous in wild
state in Australia, but. instead of con-
fining itself TO subduing the Australian
plague of rabbits, it now causes great
slaughter of sheep. The weasel and
the sloat which New Zealand people
have imported from England to keep
down the rabbits, have multiplied SO
rapidly that the remedy IS expected to
become worse than the original afllic-
ton in very short time.
Researches in France by Dr. Schultz
have shown that citric acid possesses
powerful antiseptic properties, which
may give it an important place as 9
| IOOu-pEcSelSIu0 ouUStuuSc, oluCo ~ IL
believed to be free from the objection
of unwholesomeness urged against 9th,
er antiseptic acids. Meat fragments
placed in five per cent. solution OF
the acid were in a perfect state of pres
ervation at the end of fifteen days. Ey-
perimenting upon organized germs,
| DR.. Schultz found that one drop of a
solution of one part acid to 1000 parts
water placed in liquid containing
bacteria and other forms of microscop-
ic life, instantly caused their death.
Mons. Balland has found that the av-
erage moisture of the 1ours of COM
merce is fourteen per cent. 1t varies
with the hygrometric state of the air,
and is generally from one to two per
cent greater in winter than in sum-
mer.
Oil is now extracted from the seeds
of grapes in Italy. Young grapes yield
most, and black kinds more than
white.