©54 Messrs . Allen and Pepys on the Changes produced in 
the lungs was driven into the mercurial gasometers for 
twenty-seven minutes, the temperature of the quicksilver at 
the end of the experiment was not raised half a degree of 
Fahrenheit's thermometer. The deficiency, in our opinion, 
principally arises from the difficulty in bringing the lungs 
precisely to the same state after, as before the experiment ; 
and it must be recollected that the operator commenced by a 
forcible expiration into the open air, but finished by a forcible 
expiration into the mercurial gasometer. Now, although this 
gasometer was counterpoised by weights in the scale at- 
tached to it, yet we can easily conceive that more resistance 
might be afforded to the complete evacuation in the latter 
case than in the former, and consequently the lungs might 
contain a few inches more after the experiment than before 
it, which might in some measure account for the deficiency. 
In the eleventh experiment, portions of gas were taken 
off from each of the mercurial gasometers as they were filled, 
and these portions being afterwards mixed were carefully 
examined. 
Eleventh Experimen t. 
t, Thermom. Cubic Inches q,e; c inches n . 
Barom. F a ht Time, of common air Expired Deficiency. 
Inspired. ^ 
30,4 50° 11 min. 3460 343 7 2 3 
To prevent repetition, we shall here state that all the trials 
were made in the same manner, and with the same apparatus, 
namely, the Eudiometer, described in the Society's Transac- 
tions for 1S07, in which one cubic inch is divided into one 
hundred parts ; and that in almost every instance we made 
two, and sometimes three experiments on the same gas, and 
