10 Mr Barcroft, Apparatus for Analysis of the Gases , etc. 
with froth. In use the end (d) of the gas-main is drawn off; 
(c) is blown on to the tube leading to the gas-pump. The 
end (/) of the blood-main is blown on to the measuring burette. 
To pump off the gases it is only necessary to open the two-way 
taps between the chamber and the gas-main and set the gas-pump 
going. 
Fig. 8 represents the apparatus as it appears when actually 
in use, as also does the photograph, Plate I. The stand is made 
to hold two receivers A and V, used for arterial and venous blood, 
respectively. The receivers have, from time to time, had a 
variable number of chambers, V being shewn with six and A 
with three in the plate. 
The tube leading from the drying chamber of the pump 
(seen in perspective and dotted in but really horizontal, or if 
inclined, inclined in the other direction in order to let any aqueous 
vapour which condenses fall into the lower part of the drying 
towers) is supplied with a horizontal T-piece ( xy ). At x and y 
respectively the gas-mains of the receivers are blown on, making 
one horizontal tube the whole length of the apparatus. The 
part of the blood-main adjacent to the burette is bent through 
an angle of 90° in the horizontal plane, in order to allow the tube 
at the other side of the burette to project towards the table on 
which the animal is lying. The end of this tube is shewn at e. 
It is convenient to suspend the “receivers” by strips of chamois 
leather and drawing-pins, instead of any more rigid support, which 
might throw a strain on the apparatus. 
Surrounding the lower “ bulb ” of each chamber is shewn, in 
various positions, a bag. This bag is made out of water-proof 
material bent on to a ring of wire at the top and gathered in at 
the bottom. This bag is to hold warm water or warm sponges. 
The Gas Analysis Apparatus. 
In conjunction with this apparatus, the analysis of the gases 
has been carried out by an apparatus devised and described by 
Dr John Haldane, F.R.S. The description will be found in the 
Journal of Physiology, Volume xxn., p. 456. 
