546 Royal Society :— 
With the view of preparing the glycerine from this fluid, I 
mixed 56 grms. or 1 equiv. of it, with 105 grms. or 3 equivs. of 
acetate of silver, adding at the same time some crystallizable 
acetic acid, introduced the mixture into a glass globe with long 
neck, and exposed it to the temperature of 120° Cent. for six 
days. At the expiration of this time, the greater part of the 
silver was converted into bromide; but it was not possible to 
separate from the product of the reaction a single drop of flud 
boiling above 200°. This attempt then to obtain the glycerine 
of the acetylic series failed. Is the negative result to be attri- 
buted to some accidental circumstance, as, for example, the em- 
ployment of too weak acetic acid in the process; or does it ap- 
pear to indicate that the bromine compound on which I operated 
is not really the homologue of the terbromide of allyle? I am 
disposed to be of the latter opinion. Indeed, one cannot fail to 
notice the remarkable resemblance that exists between the pro- 
perties of the bromine compound I have obtained, and those of 
the bromure d’ ethylene bromé, obtained and described by M. Wurtz. 
These bodies have the same odour, the same density, and the 
same boiling-point. But we know that the bromure d’ethyléne 
bromé, C* H® Br, Br?, is the homologue of the bromure de propylene 
bromé of Cahours, C® H® Br, Br?, and not that of the terbromide 
of allyle. If then the body obtained by me is really identical 
with that obtained by M. Wurtz, we must come to the conclu- 
sion that the iodide of allyle, submitted to the action of bromine, 
behaves in a different manner from the iodide of acetyle, which 
is usually regarded as its homologue. 
Paris, November 25, 1857. 
LXIII. Proceedings of Learned Societies. 
ROYAL SOCIETY. 
[Concluded from p. 479.] 
April 2, 1857.—The Lord Wrottesley, President, in the Chair. 
HE following communication was read :— 
“On the Application of Parabolic Trigonometry to the Inves- 
tigation of the Properties of the Common Catenary.” By the Rev. 
James Booth, LL.D., F.R.S. 
April 30.—The Lord Wrottesley, President, in the Chair. 
The following communication was read :— 
“Inquiries into the Quantity of Air inspired throughout the Day 
and Night, and under the influence of Exereise, Food, Medicine, 
Temperature, &c.”” By Edward Smith, M.D. 
This communication consists of three parts, and contains the results 
of 1200 series of observations. The author was himself the subject 
of all the investigations. He is thirty-eight years of age, six feet in 
height, healthy and strong, and with a vital capacity of the lungs of 
280 cubic inches. 
