512 
NATURE 
vrs + 
[ Oct. 16, 1873 . 
The Frog belongs to the Batrachian order Anoura, to the 
family Ranide, and to the genus Kana. ; 
The order Anoura, to which all frogs and toads belong, isa 
remarkably homogeneous one, consisting as it does of a multitude 
of species, all differing from each other by comparatively trifling 
characters. ; 
Altogether there are about 600 species of frogs and toads, 
arranged in about 130 different genera. 
St. GroRGE MIvART 
(To be continued.) 
- 
FEAN CHACORNAC* 
6 egy eminent French astronomer died on the 6th of 
last September, having been born at Lyon, June 21, 
1823. Chacornac is chiefly known for his discoveries 
among the planetoids whose orbits are contained between 
those of Mars and Jupiter. In his earlier years he devoted 
himself to commerce, but having, in 1851, made the ac- 
quaintance of M. Valz, Director of the Marseilles Ob- 
servatory, Chacornac became an enthusiastic student of 
astronomy, devoting himself to research in connection 
with the solar spots and to the assiduous exploration of 
the heavens. Onhis discovery of a new comet on May 15, 
1852, he made up his mind to abandon commerce and 
devote himself entirely to astronomy. 
In 1852, M. Valz, following the example of Mr. Hind, 
had drawn some charts of the region of the heavens in 
which the small planets were likely to be met with, and 
on Chacornac taking the above decision, Valz entrusted 
to him the construction of the “Atlas écliptique.” 
Chacornac commenced his observations on the region 
of the small planets on June 1, 1852, and on September 20 
he discovered Massalia, and on April 6, 1853, Phocza, 
and that with an equatorial telescope of only thirteen 
centimetres aperture. 
The poor resources which were at the disposal of the 
Marseilles Observatory did not permit of M. Valz’s under- 
taking the publication of the ecliptic charts ; and for this 
purpose he addressed the Academy of Sciences, which 
had appointed a commission to examine the question. 
M. Le Verrier, who at this time sought to reform the 
personnel of the Paris Observatory, called to his aid 
M. Chacornac, who, on March 4, 1854, was appointed 
Adjoint Astronomer. 
At the Observatory of Paris, Chacornac had at his 
disposal an equatorial of 7in. aperture, equal to that 
of Mr. Hind; he set down in his charts stars up to 
the 13th magnitude, and the limits which they embraced 
were at the same time somewhat extended. The publi- 
cation commenced very soon after, and from 1854 to 1863, 
thirty-six charts, of which some contained not less than 
3,000 stars, were put into the hands of astronomers. 
During the construction of these charts, Chacornac 
discovered many small planets—Amphitrite (March 3, 
1854), Polymnia (October 28, 1854), Circe (April 6, 1855), 
Lydia (January 12, 1856), Laetitia (February 8, 1856), 
Olympia (September 12, 1860), At the same time he 
observed all the comets which were then visible and 
defined, with the telescope of Foucault, of 80 centi- 
metres, many spiral nebula, previously studied by 
Herschel. The drawings of M. Chacornac are among 
the most careful we possess, and appear to show that 
nebulz of this kind undergo in time slight variations 
of form. 
This collection of remarkable works brought to the 
Astronomer of the Paris Observatory many academic and 
honorary rewards: thus, he obtained the Lalande Prize 
in 1852, 53, 54, 55, 56, 60, and 1863, became titular astro- 
nomer February 22, 1857, and Chevalier of the Legion of 
Honour, August 15, 1857. 
* From an article in La Revue Scientifique, by M. G. Rayet, Chief As- 
ronomer of the Meteorological Service at the Paris Observatory. 
| own hands a telescope of three metres focus, by 
His labours, however, and their attendant anxieties, — 
told upon his health. After going to Spain, where he went _ 
to observe the total eclipse of the sun of July 18, 1860, 
the ecliptic charts were issued less frequently, and in June, 
1863, he quitted the Observatory to retire to Ville Ur- 
banne, in the suburbs of Lyon.” ona 
In his country retirement, M. Chacornac, whose spirit 
had preserved all its activity, constructed with his” 
means of which, until within the last few months, he 
assiduously observed the solar spots and their manifold 
transformations. In the description of their incessant — 
changes he sought new proofs of the gaseous nature of 
the sun, an idea which he was one of the first to_ 
announce. ' 
SCIENCE LECTURES AT CAMBRIDGE 
‘THE following Lectures in Natural Sciences will be 
given at Trinity, St. John’s, and Sidney Sussex 
Colleges during Michaelmas Term, 1873 :— 
On General Physics and Mechanics, By Mr. Trotter, 
Trinity, in Lecture Room No. 11 (Monday, Wednesday, — 
Friday, at 11, commencing Wednesday, Oct. 15). 
On Elementary Organic Chemistry. By Mr. Main, 
St. John’s (Tuesday, Thursday, Saturday, at 12, in St. 
John’s College Laboratory, commencing Thursday, Oct. 
16). Instruction in Practical Chemistry will also be given. 
On Paleontology (the Protozoa and Ccelenterata). 
By Mr. Bonney, St. John’s (Tuesday and Thursday at 9, 
commencing Thursday, Oct. 16). . ; 
On Geology for the Natural Sciences Tripos. Pre-— 
liminary matter and Petrology. By Mr, Bonney, St. John’s 
(Monday, Wednesday, and Friday, at 10, commencing 
Wednesday, Oct. 15.) A Course on Physical Geology 
will be given in the Lent Term, and on Stratigraphical 
Geology in the Easter Term. 
Papers will be given to Questionists every Saturday at 
11, but the first paper will be set on Wednesday, Oct. 15, 
at Ir, when arrangements will be made for further 
instruction should it be required. 
On Botany, for the Natural Sciences Tripos. By Mr. 
Hicks, Sidney (Tuesday, Thursday, Saturday, at 11, in — 
Lecture Room No. 1, beginning on Thursday, Oct. 16). 
The Lectures during this term will be on the Morphology 
of Phanerogamia. / 
A Course of Practical Physiology and Histology. By 
the Trinity Praelector in Physiology (Dr. Michael Foster) 
at the New Museums. Lectures on Tuesday, Thursday, 
Saturday, at 12, commencing Saturday, Oct. 25. 
This course is intended for those who have gone 
through a course of Elementary Biology similar to that — 
given last Easter Term. 4 
THE AMERICAN ASSOCIATION 
THe Portland Meeting of the American Association 
for the Advancement of Science was in almost every 
respect an exceptional success. Its general attendance 
was very large, and there was an unusual number of the 
older members, whose presence insures consideration of — 
the more important topics, and gives dignity and force to 
the discussions. An especial effort had been made to 
exclude all inferior communications. A regulation had 
been adopted, compelling the presentation of an abstract — 
of each paper before it was read; and the examining 
committee in determining from abstracts what papers 
should be read, exercised in general a rigorous but wise 
discretion. It will not be the case after this, as after 
previous meetings, that a considerable proportion of the — 
communications actually read will have to be ignored in 
the printed proceedings. But even under such restric- 
tions, the number of papers actually read was unusually 
