TISSOT METHOD. 61 



The Zuntz-Geppert method has been the leading method for a 

 number of years for determining the gaseous metabolism in short 

 periods of both man and animals. The method has been and is now 

 in use in a large number of clinics and laboratories, and we are indebted 

 to it for a great advance in the modern knowledge of the respiratory 

 exchange under normal and pathological conditions. 



TISSOT METHOD. 



The Tissot method of determining the respiratory exchange has 

 found greatest use in the French laboratories. In Chauveau's labora- 

 tory a large amount of work on the mechanics of respiration as well as 

 on the gaseous metabolism of man has been carried out with this 

 method. More recently it has been quite extensively applied by Amar 1 

 in the study of muscular work of various kinds. 



During a European trip in 1908, I studied the technique of this 

 method in Chauveau's laboratory in Paris, and am indebted to Pro- 

 fessor Chauveau and Dr. Tissot for the privileges accorded me at that 

 time and to Mr. Jules Mansion for much personal assistance. 



The method as described by Tissot 2 is essentially the following: 

 The subject breathes through glass nosepieces of special design attached 

 to a pair of valves which separate the inspired and expired air. The 

 expired air is conducted by means of rubber tubing into an automatic- 

 ally counterpoised spirometer. The gas collected in the spirometer is 

 sampled after the experiment is finished and analyzed by means of a 

 gas-analysis apparatus. 3 



DESCRIPTION AND USE OF PARTS OF APPARATUS. 



A description of the nosepieces, valves, and method of collecting 

 the expired air is given here in detail. 4 



Nosepieces. The nosepieces are made of glass tubing in one end of 

 which a bulb is blown. These are shown in figure 23 (A and A) con- 

 nected to the tee-piece B by rubber tubing of suitable size, this tubing 

 being of varying length to permit flexibility in use. Different sizes of 

 glass tubing and bulbs may be used to adjust the nosepieces to the 

 nostrils of the various subjects. They are inserted as deeply into the 

 nose as is comfortable for the subject and are tested by putting the 

 fingers over the open ends and attempting to exhale. 



Modified glass nosepieces. During this investigation an attempt has 

 been made to modify the glass nosepieces so that they would fit more 

 closely into the nostrils and be more comfortable. These modified 

 nosepieces are shown in figure 24. They are made of ordinary glass 

 tubing with a flat bulb blown at one end. The nosepiece is bent so 



Mimar, Journ. de physiol. et de pathol. gen., 1913, 15, p. 62. 

 "Tissot, Journ. de physiol. et de pathol. gen., 1904, 6, p. 688. 

 3 Tissot, Traite de Physique Biologic, Paris, 1901, 1, p. 717. 

 4 For description of apparatus for alcohol check tests, see p. 80. 



