RESPIRATOR Y CHANGES IN AIR. 
697 
the respiratory exchange in animals. It has the advantages and most 
of the disadvantages above mentioned. The human respiration apparatus 
in the physiological laboratory, Oxford, has been constructed on the 
H2S04 
Fig. 64. — Diagram of the human respiration apparatus in the Physiological Laboratory 
Oxford. — A. To Aspirator. 
principle of Pettenkofer's apparatus, but has been made more exact and 
simple by the use of Haldane and Pembrey's method of determining 
carbon dioxide and moisture. 
A more exact method is that introduced by Haldane. 1 It is a 
Fig. 65. — Haldane's respiration apparatus. — 1 and 4, soda lime ; 2, 3, and 5, pumice 
soaked in sulphuric acid ; Ch, chamber for animal ; M, gasmeter : J, water mano- 
meter ; P, aspirator. 
modification of the apparatus used by Scharling and Pettenkofer, but 
the chief sources of error have been ehminated or greatly diminished, 
and the method has been made extremely simple. The construction is 
shown in Fig. 65 : — 
1 Journ. Physiol., Cambridge and London, 1892, vol. xiii. p. 419. 
u 
