NO. 



AIR AND TUBERCULOSIS HINSDALE 63 



an increase of pressure lowers the rate and the volume of air 

 respired. The effects of the respiration of rarefied air and com- 

 pressed air on the circulation and on the composition of the blood 

 are very marked and are of a complex character owing to the addi- 

 tional influences of the abnormal pressure on the peripheral circula- 

 tion. Not only is the circulation affected but, in the case of residence 

 at high altitudes, the proportion of red blood corpuscles and of hemo- 

 globin is notably increased. This increase in the red blood count 

 at the higher altitudes, while not so great or so permanent as was 

 at first supposed, is an established clinical fact and adds undoubted 

 strength to the claim that altitude per se is a characteristic of the 

 favorable climate for tuberculous patients. 



DIMINISHED ATMOSPHERIC PRESSURE 



The influence of diminished atmospheric pressure on the blood has 

 been studied by Paul Bert in 1882,' Zuntz,' P. Regnard,' Viault," 

 Egger,' Woolff," Koeppe,' Solly,' by W. A. Campbell and Gardiner 

 and Hoagland," by L. S. Peters'" and by F. Laquer." One of the 



' Paul Bert, loc. cit., studied the blood of animals at La Paz, in Mexico, 

 at an altitude of 12,140 feet (3,700 meters) and found that they had an 

 oxygen-carrying capacity far in excess of that exhibited by the animals on 

 the lower plains. 



" Zuntz : Experiments on the Pic du Midi, Elevation 9,000 feet. He empha- 

 sized the possibility of an altered distribution of corpuscles. 



^ Regnard, P. : La Cure d'Altitude, 2eime Ed. Paris, i8g8. 



*Viault: Experiments at Merococha, Peru, elevation 14,275 feet. 1890. He 

 noted that his blood contained 7 to 8 million red corpuscles per cubic milli- 

 meter. 



"Egger: The Blood Changes in High Mountains, Verhandlungcn d. xii, 

 Congr. Inner. Med., 1893. 



° Woolff: Verhandlungen d. xii. Congr. Inner Med. 1893, pp. 262-276. 



' Koeppe, xii. Congress fiir Inner. Med., 1893 ; Arch. Anat. Physiol., 189S, 

 pp. 154-184. 



*S. E. Solly: Blood Changes Induced by Altitude. Trans, .\merican 

 Climatological Association, 1899, p. iz^; also 1900, p. 204. 

 S. E. Solly, Therapeutic Gazette, February, 1896. 



" Campbell and Hoagland : Trans. American Climatological Association, 

 1901, p. 107. 



" For the effect of altitude, 6,000 feet, on blood pressure in tuberculous 

 patients, see article by L. S. Peters, Silver City, New Mexico, in Archives 

 of Internal Medicine, August, 1908 and October, 1913. The latter report 

 covers 600 cases and shows that altitude tends to raise blood pressure rather 

 than lower it both in consumptives and in normal persons living at high 

 altitudes. 



"F. Laquer: Hohenclima und Blutncubildung, Deutsches Archiv fiir klin. 

 Med. Leipzig, 1913, ex, Nos. 3 and 4, p. 189. 



