(Ce KANSAS CITY REVIEW OF SCIENCE. 
ing the horizon just after sunset, reaching one-third of the way around. At per- 
ihelion, it was nearer to the surface of the sun than any known comet, save that 
of 1680, and both of them swept in nearer than the solar corona.” 
It was estimated by Newton that the comet of 1680 was subjected at perihel- 
ion to a heat equal to 2,000 times that of red-hot iron. 
The discussion of this comet made by Prof. J. S. Hubbard, and publieneds in 
Dr. Gould’s Astronomical Journal, Vol. 1., is pre-eminently the authority concern- 
ing it. Much difficulty was encountered in an attempt to fix its orbits, owing to 
the shortness of time for observation, proximity to the horizon, and the slowness 
of its motion. ‘The peculiarity producing the most remark was the smallness of 
its perihelion distance, resembling the comet of 1680, while its physical character- 
istics resembled the comet of 1668. In concluding his discussion (Vol. i1.), Prof. 
Hubbard states as follows:—‘‘So far as the data employed and the calculations 
based upon them can be relied upon, the hypothesis of the identity of this comet 
with that of 1688 is not sustained.’’ The probable error of a single observation 
of his computed orbit was determined by Hubbard to be = + 107.62, and con- 
sidering also the probable error belonging to an orbit of 175 years, the difficulty 
stated by Nicholai shows itself, viz.: that ‘‘ the transition from a period of 175 
years to one of infinity, makes almost no difference in the representation of ob- 
servations.” So small a portion of the orbit is it withm our power to observe, 
that the differences in the observations upon a long orbit and those on an infinite 
curve are extremely difficult of determination. In the consideration of the comet 
of 1880 and its discussion, the observations made in 1843 may be of the gr eate 
importance.—Scéence Observer. 
CORE 2S POND ENCE. 
SCIENCE LETTER FROM FRANCE. 
ATMOSPHERIC DUST—-KLEPTOMANIA—HUMAN HEAT—PHOSPHORESCENCE. 
Paris, April 13, 1880. 
The Scientific Association of France has resumed its instructive Saturday 
Evening Conferences at the Sorbonne, our Royal Institution, under the presi- 
dency of the celebrated and indefatigable M. Milne Edwards. ‘The subjects 
selected are of every day, living interest, are the specialty of each lecturer, and 
are handled in a popular manner and illustrated with every suitable apparatus. 
M. Jamin has expounded the latest discoveries in telephones and phonographs; 
M. Egger has deciphered the recent papyrus finds in Memphis; M. Bouley has 
examined the question of rabies, and M. Gaston Tissandier, of elevated balioon- 
ing notoriety, has revealed many interesting facts on atmospheric dust, its con- 
nection with cosmical matter, and the important réle it plays in fermentation and 
