Royal Society. 48} 
" Jation. His first paper on this subject, observed the learned 
President ‘*was perfectly satisfactory to men of science; 
but some men of letters having expressed doubis, his se- 
cond entirely removed them.” Sir Joseph concluded his 
elogy by recommending the labours of the Society for im- 
proving animal chemistry, of which Mr.B. is a member, 
and which considering itself a young protegee of the Royal 
Society, had furnished the transactions of the latter with 
many valuable papers in a department of science almost 
entirely new. 
Dec. 9. The Society assembled after the anniversary, and 
the minutes of the former meeting were read, detailing the 
election of officers, the names of newly elected or deceased 
members, &c. 
Dec. 16 and 23. The President in thechair. .A long se- 
ries of experiments on some affections of light was read, in 
a letter from Dr. D. Brewster toSir Humphry Davy. Dr. B. 
in continuation of his experiments on light, and the refrac- 
tive powers of different substances, details the result of his 
observations on what he called ¢* hammer agate,” in a plate 
the 1100dth part of an inch in thickness. The experiments 
were extremely minute and numerous, and his observations 
on the polarization and depolarization of light could not 
be rendered intelligible in an abstract of a few lines. Light 
in the rainbow he considers as completely polarized: that 
reflected on the earth with a blue sky is less so. Iceland 
spar depolarized the lights which was polarized by the agate. 
He considered the polarizing, depolarizing, and neutral axes 
in the agate as affecting the colours, and producing red, 
green, &c. rays. N.B. It appears not to have occurred to 
Dr. B., Dr. Herschel], or Mr. Jordan, that the pencils of 
_ rays and coloured rings depend on the ¢hickness of the glass 
or other transparent bodies used in such experiments. 
Mr. Anthony Carlisle, in a letter to the President gave 
an account of the family of Zerah Colburn, the mathema- 
tical boy, whose father and great-grandmother had five fin- 
gers and a thumb on each hand and six toes on each foot. 
The supernumerary limbs are attached to the little fingers 
and little toes of the hands and feet, each of these addi- 
tional members having complete metacarpal and mctatar- 
sal bones. Zerah Colourn, who isthe fourth generation of 
his family known with this appendage, has three brothers 
in the same state, and two brothers and two sisters with 
the regular limbs. Some of the family have wanted one of 
the supernumerary fingers or toes, but their descent has 
been tolerably uniform. This youth and parents are natives 
Vol, 42, No. 188, Dec. 1813, Hh of 
