[ 340 ] [Nov. J ? 
PROCEEDINGS OF PUBLIC SOCIETIES, 
THE ROYAL SOCIETY OF LONDON. 
N the last part of the Transactions of 
the Society, there is a veiy interest¬ 
ing essay on the compounds of chlorine 
and carbon, by Mr. Faraday, chemi¬ 
cal assistant in the Roval Institution : 
* 
there is also a communication from Dr. 
Henry on the aeriform compounds of 
charcoal and hydrogen. 
In Physiology we are principally in¬ 
debted to the indefatigable exertions 
of Sir Ever ard Home. This part con¬ 
taining two communications from Sir 
Everard upon physiological subjects; 
and under the same head we may class 
ail account of the urinary organs of two 
species of frogs, by Dr. Davy ; and 
two letters addressed to the President, 
showing a singidar influence of the male 
upon tiie progeny of the female. 
One geological paper is contained in 
this part of much curiosity, and some 
importance. The mountain limestone 
of Plymouth lies directly upon clay- 
slate, and is remarkably scanty in or¬ 
ganic remains; it includes certain ca¬ 
verns, perfectly insulated, some of 
which are incrusted with stalactite, and 
resent nothing remarkable, In others, 
Ir. Whidbey, tlie author of this com¬ 
munication, has discovered certain fos¬ 
sil hones in caves without any stalacti- 
tical incrustation, having only a little 
dry clay at the bottom. 44 The cavity was 
entirely surrounded by compact lime¬ 
stone rock, about eight feet above high 
water mark, fifty-five feet below the 
surface of the rock, one hundred and 
seventy-four yards from the original 
face of the quarries, and about one hun¬ 
dred and twenty yards in that direc¬ 
tion from the spot wdiere the former 
bones w r ere found in 1816.” The bones 
are those of Hie rhinoceros, the bear, 
and an animal of the deer kind, and of 
another animal of the size of the bear. 
This part includes also a paper on the 
magnetic phenomena produced by elec¬ 
tricity, by Sir H. Davy, and commu¬ 
nications from Captain K ater, respect¬ 
ing a volcanic appearance in the moon ; 
and an account of a micrometer made 
of rock crystal, by Mr. Dollond. 
As black surfaces become infinitely 
more heated than w hite, by exposure to 
the sun’s rays, it has long puzzled phy¬ 
siologists to account for the black co¬ 
lour of the negro ; or to develope the 
ends attained by that intensity of co¬ 
lour bestowed by the unerring hand of 
nature upon the inhabitants of tropical 
climates. 
In a paper on the black rcte muco - 
sum of the negro, being a defence 
against the scorching effects of the sun’s 
rays, by Sir E. Home, he states that the 
blistering and irritation which Euro¬ 
peans, not accustomed to much expo¬ 
sure, suffer from the scorching ravs of 
an equatorial sun, are attributable to a 
peculiar effect of the solar radiant mat¬ 
ter, unconnected with the heat which 
it excites. By the black colour of the 
negro’s skin the radiant matter of the 
sun is absorbed, and converted into 
sensible or tiiermomefric heat, and is 
thus disarmed of its mischievous ten¬ 
dency. If we expose the back of the 
hand to very intense sunshine, unco¬ 
vered, or covered with any thin w hite 
tissue, it becomes inflamed and blis¬ 
tered; but if similarly exposed under 
a covering of black, it suffers no in¬ 
convenience, though the temperature 
in the former case falls far short of that 
excited in the latter. 
The Croonian Lecture by Sir Eve¬ 
rard Home, consists of microscopical 
observations on the brain and nerves; 
showing that the materials of which 
they are composed exist in the blood ; 
on the discovery of valves in the 
branches of the vas breve, lying be¬ 
tween the villous and muscular coats 
of the stomach, and on the structure of 
the spleen. 
Bauer examined the optic nerve, and 
found it to consist of many bundles of 
* 
fine fibres, formed of very minute glo¬ 
bules united by a soluble transparent 
jelly. 44 By the discovery of this trans¬ 
parent substance,” says Sir Everard, 
44 we become acquainted with the na¬ 
ture of the medullary structure of (he 
nerves, and can form some idea of their 
action, which till now I confess myself 
to have been totally unacquainted with. 
The nerves as w r ell as the retina are 
composed of this newly discovered trans¬ 
parent substance, which is veiy elastic 
and soluble in w ater, and globules of 
and 3 cfeoP arts of an in diame¬ 
ter. Its transparency and solubility 
account for its having remained con¬ 
cealed ; and were it not coagulable, in 
which state it becomes opaque, its ex¬ 
istence might even now be considered 
as equivocal.” The brain is also, accord¬ 
ing to Bauer, a conglomerate of glo¬ 
bules and soluble mucus, the former 
arranged 
