Zoological Proceedings of Societies. 129 
Arr. XXIV. Proceedings of Learned Societies on sulyects 
connected with Zoology. 
ROYAL SOCIETY. 
April 30, 1829.—A paper was read On the Respiration of Birds : 
by Messrs. W. Allen, F.R.S,, and W. Hasledine Pepys, F.R.S. 
The enquiries of the authours on human respiration, and on that of 
the Guinea-pig (Cavia Cobaya,) of which the details were communi- 
cated to the Royal Society in former papers, are here extended to the 
respiration of Birds, Pigeons were the subjects of these experiments, 
and the same apparatus was employed as the one used for the Guinea- 
pig, described in the Philosophical Transactions for 1809. 
The object of the first experiment was to ascertain the changes which 
take place in atmospheric air when breathed by a bird in the most natural 
manner. For this purpose a Pigeon was placed in a glass vessel contain- 
ing about sixty-two cubic inches of air, and communicating with two 
gasometers, one of which supplied from time to time fresh quantities of 
air, and the other received portions which became vitiated by respiration. 
The experiment lasted sixty-nine minutes, and was productive of no in- 
jury to the bird, except a slight appearance of uneasiness whenever the 
supply of air was not sufficiently rapid. On examining the air at the 
end of the experiment, no alteration had taken place either in the total 
volume of air or the proportion of azote which it contained ; the only 
perceptible change being the substitution of a certain quantity of carbo- 
nic acid for an equal yolume of oxygen gas, amounting to about half a 
eubic inch per minute, and being equivalent to the addition of ninety- 
six grains of carbon in twenty-four hours. 
Two experiments were made on the respiration of oxygen gas, ob- 
tained from chlorate of potash, and containing in the one case two, and 
in the other only one, per cent. of azote. Under these circumstances it 
was found that the volume of the gas was unaltered, and that a similar 
quantity of oxygen gas had been abstracted, but that a much smaller 
quantity of carbonic acid had been formed than in the last experiment, 
the remaining portion being made up by azotic gas which had been given 
Vou. V. 1 
