38 
Proceedings of the Royal Society of Edinburgh. [Sess. 
After an interval of about two minutes the tap was again turned at the 
end of an expiration. The bag was then placed on the table ; kneaded to 
mix its contents; connected to the supply pipe of the Briggs analysis 
apparatus,* B, and with the tap in the on ” position, squeezed to force a 
few litres through the burette. The sample so obtained in the burette was 
then analysed for COg. This procedure avoided the need for sample tubes 
or bottles. One of the N.C.Os. made the analysis during the time that the 
next sample was being obtained in the bag. 
After filling the burette, the bag was emptied by pressing it flat, and 
was again connected to A. The subject was required to pedal at no load, 
i.e. with the belt off, for two minutes ; the tap was turned on at the end 
of an expiration, and expired air allowed to accumulate in the bag for 
another two minutes of pedalling, when the sample was removed to the 
analysis apparatus. The belt was put in place ; its cords were adjusted 
to give a difference of 3 lbs. between the balance readings, and the same 
sequence followed. Similar observations were made at balance-differences 
of 6, 9, 12 lbs., or even more, if the man could support such heavy exertion. 
Pedalling was timed to a pendulum which swung 56 to the minute ; at 
* First Keport, “Mine Kescue Apparatus Research Committee,” 1918, p. 51. 
