RESPIRATION 



133 



A new and important light was thrown on the whole subject in 

 the course of a study by Meakins, Priestley, and myself of the 

 "neurasthenia" produced by gassing and other causes during the 

 war. 1 As mentioned in Chapter III, the breathing in these patients 

 is abnormally frequent and shallow, particularly on exertion. It 

 was also found that addition of oxygen to their inspired air was of 

 considerable service during any ordinary exertion, and that in 

 some of them the lips became blue on exertion unless oxygen was 

 given. As there was no sign of anything seriously abnormal in 

 their lungs, we were led to suspect that the shallow breathing was 

 somehow causing anoxaemia. This led us to make experiments 



Figure 43. 

 "Concertina" apparatus for continuous record of respiration. 



on the effects of shallow breathing in normal persons, and for this 

 purpose we devised the apparatus 2 shown in Figure 43. The 

 subject inspires through the mouthpiece and inspiratory valve 

 from the recording "concertina." The bottom of this moves up- 

 wards with inspiration, and records the movement by means of 

 an inked pen on the drum. The bottom comes down on a movable 

 stop, and by moving this upwards the maximum capacity of the 

 concertina can be reduced to whatever is desired. During expira- 

 tion the expired air passes out by the rubber expiratory valve. 

 At the same time the expiratory pressure is communicated to a 



1 Haldane, Meakins, and Priestley, Journ. of Physiol., LII, p. 433, 1919. 



2 Made by Messrs. Siebe Gorman & Co., 187 Westminster Bridge Road, London. 



