104 Correspondence of J. Nickles. 
appointment as Professor in the Faculty of Sciences at Paris, suc- 
ceeding Desfontaines. This was the first period of his scientific life. 
His intimate friend Duke Decaze having been named Minister of the 
Interior (in 1816), he accepted the position of general Secretary, which 
he held till. 1824. If he did not publish works during this time, he 
performed an important service to science by using his influence in 
bringing back from exile men of science who had become victims of 
political vicissitudes at the Restoration ; and through him also funds 
were given to the Museum of Natural History, to render the institution 
useful to travelling naturalists, 
eturning to private life, he took up again his researches in physiol- 
ogy. His new labors possessed a novelty, an exactness, and perfection, 
which was hardly expected of a savant, who had been so long a stran- 
ger to the progress of the science. What was especially surprising, 
was the profound difference between his new views and those of his 
youth, and also his noble frankness in acknowledging any inexactness 
he 
casion of spirited discussions with M. oe ichaud, then young, whom 
science has lost during the present year. M. Mirbel did not long con- 
tinue in this new career. He fell into imabeellity, and continued in this 
state until his death. 
Astronomical Refraction.—A memoir by M. Faye, in which he en- 
deavors to show a defect in the existing theory of astronomical refrac- 
tion and proposes a formula for correcting it, has led to an interesting 
discussion which has already continued two agua All the astrono- 
mers and the principal physi icists have taken part. M. Biot does not 
restrial refraction. M. Faye has nanan many partisans, and the 
issue of the discussion does not appear doubtful. 
Constitution of the Sun; Solar Wicichen 8 Thomson, one of 
the physicists, who with Carnot, Clapeyron, Joule, Meyer and others, 
have most largely contributed towards establishing the relations between 
heat and mechanical wr as extended his researches to the heat 
emitted by the sun; and he observes that this heat pga a res toa 
development of mechanical force, which, in the space of about 100 
movement of all the planets. ‘The author examines successively the 
different sources of heat, and ends by concluding that the solar heat 
sa ve no other than a meteoric origin, and that it results from the 
on of meteors which fall into the sun—an idea first put forth by M. 
Waterson at the meeting of the British Association at Hull. What 
rma e value of this hypothesis, we may ask whether it would 
aes simple to admit that the solar heat eatals simply from 
the Fotatory movement of the sun; Mr. Thomson admits himself that 
is necessary to the production of the heat. It is con of 
sun moves on its axis, and what use is this intervention 
meteorites, which nothing j justifies ? 
