758 Experiments 



To measure the quantity of air expired, I found nothing more 

 convenient or more accurate than a gasometer. The one I had made 

 especially for this purpose and which is pictured in Figure 63, has 

 several dials, by means of which one can estimate the volume of 

 air which has passed through the apparatus to within 50 cc. 



Fig. 63 — Gas meter for measuring respiratory movements. 



When it was necessary to measure the maximum expirations, I 

 stood up, with my garments loosened, and after the inspiration, I 

 took in my mouth, without any supplementary tube, the pipe leading 

 to the gasometer and exhaled rather slowly until the lungs were 

 empty, my nose, of course, being closed tightly by my left hand; I 

 thus made at least 10 expirations, of which I took the average. 



The same arrangement was used when I wished to exhale into 

 a rubber bag to check the quantity of carbonic acid produced in a 

 given time. I generally breathed for 10 minutes into the bags; then 

 the air from them was passed for a whole night through the potash 

 bubblers which I shall describe later; there it was completely freed 



