28 
THE j^ATURALISTS’ COMPAISriON. 
COMETS, 
Twenty comets which have been 
studied with the spectroscope have 
appeared to be essential alike in 
chemical composition, while each 
comet is continually varying in tem¬ 
perature, density and the amount of 
vapor emitted by its nucleus. Hug¬ 
gins states that the substance ot 
these bodies undoubtedly contains 
carbon, hydrogen and nitrogen, 
and probably oxygen. Meteorites 
are evidently of the same nature as 
comets, and, while consisting chiefly 
of iron and other solids, can often 
be made to give up several times 
their volume ot gasses. The idea 
that the light of comets and the phe¬ 
nomena of their tails are produced 
by electricity is gaining in favor 
among students of these subjects. 
The discovery that comets are 
celestial bodies, extraneous to our 
atmosphere, is due to Tycho Brahe, 
who ascertained the fact by obser¬ 
vations of the comet of 1557, New¬ 
ton succeeded in demonstrating that 
they are guided in their movements 
by the same principle which controls 
the planets in their orbits; and Hal¬ 
ley was the first, by determining the 
parabolic elements of a number of 
comets from the recorded observa¬ 
tions, to identify the comet of 1682 
with one which had been observed 
in 1607, and the observations record¬ 
ed by Kepler and Longomontanus, 
and also with a comet observed in 
1531 by Apian, at Ingoldstadt, and 
thus confidently to predict the re¬ 
turn, at the end of 1758 or beginning 
of 1759, of a comet which would 
have the same parabolic elements. 
The number of comets belonging to 
our system, although great, is being 
constantly augmented through the 
discovery of new bodies of this class. 
A comet was discovered by Swift, of 
Rochester, N. Y., on the morning 
of June 20,1879, first seen four days 
before, but not determined to be a 
comet until the date named. Its 
position on June 20, about 11 P. M., 
was northern declination 60 deg. 40 
min., and 2 hours, 27 minutes and 14 
seconds. Observations on the next 
evening show it to be moving almost 
due north, and almost exactly one 
degree per day. It is small and faint, 
and is probably receding from the 
sun, so that it is not likely to become 
any more conspicuous than it has 
been, though it requires longer ob¬ 
servation to determine its orbit. 
SKELETONS. 
A very excellent and simple meth* 
od for procuring the skeletons of 
snakes, small birds, mice, fish, etc., 
is to procure a common cigar box,in 
the bottom and sides of which small 
holes are bored. Place the speci¬ 
men of which the skeleton is desired 
in the box and bury it in an ant hill. 
The ants will enter through the holes 
in the box and eat away all the 
flesh, muscles, etc., leaving the per¬ 
fect skeleton as tne result. The 
skeleton should be placed in water 
for two or three days to extract the' 
bloody color, then whitened with 
lime and alum and dried. It will 
require a week or ten days for the 
ants to clean the bones of the meat. 
Iridium-—Found native as an alloy 
with osmium in lead-gray scales,and 
is the heaviest of known substances, 
$1,090 lb.— HoosierM. & 4, 
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