Medical Apparatuses 433 



12. The changed activity of the diaphragm and the thorax per- 

 sists after the end of the experiments. 



13. These increases do not take place solely in extreme respira- 

 tions; they are observed in the regular respiration, and the diaphragm 

 then is also lower than in the normal state. 



14. The respiration becomes less frequent. The number of the 

 movements decreases by 1 to 4 per minute. This effect continues a 

 little while after the return to normal air. 



15. 16, 17, 18. These sections repeat for frequency what was 

 said about depth in 10 to 13. 



19. The inspiration is faster, the expiration slower; the first 

 part of the latter is rather short, but the second becomes so slow 

 that there seems to be a pause. 



20. The proportion of carbonic acid contained in the expired 

 air increases; a respiration with 3/7 of an atmosphere above the 

 normal contains on the average 22.26% more carbonic acid than at 

 normal pressure. 



21. This increase therefore is not in exact proportion to that 

 of the pulmonary capacity, which is 3.3%. 



22. It takes place not only in exaggerated respiratory move- 

 ments but also in quiet respiration. 



23. Upon comparing this increase of carbonic acid with the de- 

 crease of respiratory frequency, we see that there is definitely a 

 greater quantity of carbonic acid given off and consequently of 

 oxygen absorbed. 



24. The result of this is that after a series of treatments in com- 

 pressed air, the venous blood appears brighter, the temperature of 

 the body increases (from 0.1° to 0.4°), the muscular energy is 

 greater, hunger appears, and, in spite of a larger amount of food, 

 the weight of the body lessens through emaciation; however, if the 

 pressure is not too great and if one eats a great deal, one may, on 

 the contrary, grow fat. 



25. The pulse rate drops by 4 to 7 per minute; this decrease 

 is still more marked when there was an abnormal acceleration. 



26. On return to open air, the pulse resumes its normal rhythm. 



27. However, when the frequency of the pulse was due to some 

 respiratory difficulty, a permanent drop may be the result of treat- 

 ment by compressed air. 



28. The decrease of the frequency of the pulse seems to be the 

 result of the purely mechanical action of the compressed air; the 

 increased pressure on the surface of the boody increases the re- 

 sistances met by the blood waves sent out by the systole of the 

 heart; the systole then becomes more difficult, with the result of a 

 decrease in the number of pulsations. 



29. The curve of the radial pulse undergoes changes in form; 

 its height lessens, the line of ascent is less steep, more oblique, the 

 apex more rounded, the line of descent loses its wavy form and be- 

 comes straight or slightly convex. There is therefore a shrinkage 

 of the vessels, and consequently of the quantity of blood which 

 they contain, an increase in resistance to the systole of the heart, 

 and a greater difficulty in the capillary circulation. 



