88 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 63 



But the consequent increased atmospheric pressure in these localities 

 is not in itself worthy of note. Such desolate regions as the Dead 

 Sea, the Mojave Desert, Death Valley, and Salton Lake, California, 

 are entirely unsuited for the tuberculous, and, for obvious reasons, 

 all subterranean pressures are out of the question. Divers and 

 caisson workers become anemic and hence artificial pressures in- 

 creased beyond the normal at sea level are injurious. 



Even the natural variations in atmospheric pressure at any given 

 station may be sufficient to have some appreciable influence, per se, 

 on the course of pulmonary tuberculosis. Changes of pressure of 

 20 mm. (.7874 inches) occasionally take place, but they are com- 

 parable to a gradual change of level amounting to only 200 meters 

 (656 feet), and it has been assumed that no appreciable physiologic 

 eft'ects can be attributed to these gradual alterations, at least as far 

 as tubercular diseases are concerned. Hann ^ and Thomas ^ state 

 that in experiments with pneumatic chambers, pressure changes 

 amounting to 300 mm. (11.8 inches) a day have been produced 

 without causing any notable injurious effects upon the sick persons 

 concerned in these experiments. 



EFFECT OF BAROMETRIC CHANGES ON THE SPIRITS 



As the barometric pressure in any given place falls the cloudiness 

 usually increases, the temperature rises, the wind increases, and 

 precipitation is liable to occur ; as the pressure rises the skies clear, 

 the temperature falls and the winds shift to the west or northwest. 

 The spirits and general morale of all patients usually improve with 

 a rising barometer unless prolonged wind storms accompany such a 

 change. Whatever improvement accompanies a rising barometer 

 is due to the stimulus of cold or the return of sunshine and dryer 

 air. 



Dr. Charles C. Browning, of Los Angeles, has studied the effect 

 of some atmospheric conditions on tuberculous patients.' In his 

 first report it appeared that unseasonable or very sudden changes 

 in temperature influenced temperature of patients, while equal or 

 greater changes occurring slowly did not. Of hemorrhages occur- 

 ring in groups about four times the number occurred when there 



'Julius Hann: Handbook of Climatology, Macmillan, 1903, p. 71. 

 ^Thomas, in Beitrage zur Allgemeinen Klimatologie, Erlangen, 1872. 

 ■* Trans. American Climatological Ass., 1908 ; idem, 1913, p. 189. 



