420 Historical 



It is quite evident that such changes in the pulmonary capacity 

 must have some effect upon the sum total of the respiratory func- 

 tions, and particularly upon the number, the depth, and the rhythm 

 of the respirations. 



The number first: 



In my first experiments published several years ago, I had al- 

 ready found the number of inspirations diminished; my long present 

 series of experiments has confirmed this result, as being constant, one 

 may almost say. The decrease in the number of inspirations varies 

 with the individual. On the average, it increases proportionately 

 with the original number of respirations; in general, it is 3, 2, 1, 

 to Vz respirations per minute. As a maximum, I have observed in 

 two patients with emphysema, whose inspirations rose to 33 per 

 minute, a decrease which was respectively 16 and 11 inspirations. 



Upon the return to normal pressure, the number of inspirations 

 increases again a little, but without reaching its original figure. In 

 that also, the effect of the compressed air is not merely temporary, 

 but has a somewhat permanent quality. This is more evident when 

 we consider the frequency of the respiration in a longer series of 

 observations. Then we note that the respiration is always less -fre- 

 quent the day after than on the day before. As it undergoes a new 

 decrease as a result of each new treatment with compressed air, the 

 result is this certain and constant fact that the continued use of com- 

 pressed air lessens the frequency of the respiratory movements every 

 day, up to a certain limit. 



My own respiration, after three months of daily use of com- 

 pressed air for two hours every day, had fallen from 20-16 per min- 

 ute to 4.5 under normal pressure, and even to 3.4 in compressed air. 



When it had reached this degree of slackening, it remained 

 stationary during the subsequent experiments (still slackening a little 

 under the influence of pressure) and even now, while I am writing 

 these lines, although 5 months have passed since then, my respira- 

 tion does not exceed the noteworthy figure of 5.4 inspirations per 

 minute. The same result, though less remarkable, because the series 

 of experiments was shorter, was noted in observations made on other 

 people. In M. H. .y, the number of inspirations had fallen in 12 days 

 successively from 21 to 16 and in compressed air to 13 per minute. 

 In Dr. Lange, after 4 treatments taken in 11 days (in spite of interrup- 

 tions of several days) from 19 to 16, and in compressed air from 14 

 to 6; in M. G., an emphysematous patient, after 14 treatments taken 

 in 19 days, from 20.5 to 15.5; in Dr. D., also emphysematous, from 33, on 

 the second day, to 18, and in 5 days to 10.4. 



It is during the first days that the respiratory frequency lessens 

 most noticeably and most promptly; later, the decrease becomes 

 slower and the differences less great. 



If we compare the result obtained as to the frequency of the 

 respiration with the result given us by the spirometer, it will be dif- 

 ficult not to observe that there is between the two a well-founded 

 relation, that the frequency of the inspirations is inversely propor- 



