THE TABLES: EXPLANATORY 



apparatus that affords the least possible resistance to 

 expiration, and at the same time gives easy and accurate 

 readings of the amount of air expired. The most suitable 

 apparatus has been found to be a spirometer made by 

 Georges Boullite of Paris* (Fig. 2). 



Fig. 2. Spirometer. 



Naturally, however, any accurate apparatus having 

 the same advantages can be used. A flexible tube of 

 sufficiently large diameter (about 2 cm. or in.) should be 

 attached to the apparatus. In the free end of the tube is 

 inserted a tight-fitting mouthpiece (indiarubber tubing) 

 7 or 8 cm. (3 in.) in length and about 2 cm. in diameter. 

 After use these mouthpieces should be placed in a solution 



* British Agency, Oxford Scientific Instrument Works, Whealslicaf 

 Yard, Oxford. 



