328 NOTES ON HISTORY AND CLIMATE OF NEW MEXICO. 



physical fatigue. He does so, however, at a very rapid rate, and a 

 quickened respiration is the result. Dyspnoea (besoin de respirer) results 

 from any change of accustomed relations between the lungs and the air 

 to be respired. It occurs in pregnancy ; (in dropsical accumulations, 

 abdominal or thoracic, which obstruct the expansion of the chest and 

 lungs, and limit the free play of the muscles of respiration and fatigue 

 them.) Emotional disturbances, nervous perturbations, and mental anx- 

 iety cause it, as well as any undue physical labor or unwonted exertion. 



That the respiration of an atmosphere of 8,000 feet above sea-level 

 need not necessarily involve dyspnoea in an individual, I know from per- 

 sonal experience. I visited this country, ascending 8,000 feet, in 1849, 

 and lived at an elevation of between 6,700 and 7,000 feet for three years. 

 Again, in the past year (1875) I revisited New Mexico, and I have never 

 detected in myself any disturbance of respiration as the effect of this 

 altitude — not even a quickened respiration. I am not unmindful of the 

 fact, however, that another person may have a different experience, but 

 it may, perhaps, be attributable to other causes than altitude, or as com- 

 bined with it. 



The amount of oxygen present available for respiration may be in some 

 degree dependent upon the stagnation or relative movement of the air. 

 A moveless atmosphere becomes very oppressive, and perhaps is most 

 prevalent in low countries. The movement of the air is, as a rule, 

 greater in the mountains and high altitudes generally. I invite atten- 

 tion in this connection to the Chief Signal-Officer's remarks for October, 

 1874, (page 285, report for 1875 :) " The extreme maximum movements 

 of the wind have been, at Breckenridge, 7,050 miles ; at Cape Henry, 

 9,147 ; Cape May, G,907 ; Cleveland, 7,281 ; Escanaba, Mich., 7,217 ; 

 Long Branch, 9,242 ; Pike's Peak, 14,734 ; Sandy Hook, 10,917. The 

 extreme minimum movements have been, at Memphis, 1,700, and at 

 Shreveport, 1,880- The calm area is therefore coterminous with that of 

 high pressure." 



That high temperature produces oppression in breathing is evidenced 

 in the East Indies both in the periods of calm and during the prevalence ot 

 the hot winds, especially when, as happens in midsummer, the thermome- 

 ter reads higher at night than in the day-time. At Nowshera, in 18G7, the 

 condition of the troops is described as " gasping for breath. There was 

 a peculiar feeling of weight on the chest, even in the apparently healthy; 

 and after every 20 inspirations, or thereabout, a strong and convulsive 

 effort was necessary to inflate the lungs. * * * When the cause, 

 viz., prolonged high temperature, was removed, an almost instantaneous 

 return to health (in cases of insolation) was the result." (British Army 

 Med. Dept. Eeport for 1868, Appendix No. X, pp. 296, 297, by Asst. 

 Surg. Staples, 19th Regt.) 



" In the same way that we cannot endure either constant dryness or 

 dampness, so we cannot endure a very constant state of the barometer 

 without suffering in our breathing or nerves. In fact, there is little 



