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XXX. Proceedings of Learned Societies. _ | 
ROYAL SOCIETY. 
Jan. 27. Tue Right Hon. President in the chair. A long pa- 
per by Dr. Brewster was read, giving a detailed account of his 
numerous experiments en light, in addition to those which have 
already been laid before the Society. Dr. B. has investigated 
with great care the laws which govern the reflexion of light, and 
ascertained that its polarization discovered by Malus is not a ge- 
neral but a particular law. The phenomenon of double reflexion 
has engaged his attention, but it is not possible to convey any 
adequate idea of his new observations and discoveries without 
drawings in this brief report. 
Feb. 3. Sir Humphry Davy communicated to the Society a 
tong account of his very accurate and ingenious experiments on 
the fluoric principle. Fluor is one of the many substances which 
present great difficulties to the inexperienced operator, and pro- 
mise no brilliant results to reward his labour; consequently it 
remained almost unexamined till the important discoveries of this 
philosopher naturally led him to investigate its nature and pro- 
perties. His former experiments developed many new and cu- 
rious analogies of nature ; his present confirm the observation that 
hydrogen produces as many acids as oxygen, and that it unites to 
the peculiar base, which he ealls fluorine, to constitute fluorie 
acid. His first opinion, founded on analogy, that siliea and boron 
were metals, he here abandons, and considers them also as pecu= 
liar undecemposed substances, which, in the present state of our 
Knowledge, must be admitted as elements, the same as oxygen, 
hydrogen, chlorine and fluorine. The result of many complex 
and delicate experiments is, that fluo-borats can never be pro- 
duced without the aid of hydrogen; and finally that, contrary 
to the supposition of Berzelius and others, who have argued the 
point with at least as much zeal for distinction as truth, chlorine 
contains no oxygen. 
A short paper by Mr. A. Carlisle was read on Monstrosities, as 
an appendix to his remarks on Zerah Colbourn ; ‘the purport of 
which was, that both sacred and profane history record examples 
of hereditary monstrosity, particularly in supernumerary fingers 
and toes ; and that these extra-appendages are generally attached 
to the outer side of the hands and feet, very rarely to the inner, 
and almost never to any other limb. 
Feb. 10. Mr. Brodie (through the Society for promoting a 
Knowledge of Animal Chemistry) communicated an account of 
his observations and experiments on the influence of the nerves on 
glandular secretion, particularly that of the 8th pair. In conse- 
quence 
