304 Historical 



tion which cannot be less than 3800 meters, but which, in the latitude 

 of Peru, must be the line of perpetual snow? If this phenomenon 

 appears, is it only temporary during the ascent, or does it persist after 

 the summit has been reached? 



7. When the dwellers on the heights descend to the plains and 

 toward sea level, do they experience a disturbance in their functions, 

 and of what does this disturbance consist? 



8. Is a mental disturbance corresponding to the physical disturb- 

 ance, or discouragement, or irritability of temper often observed? 



9. Are the symptoms of the soroche the same on the eastern and 

 western slopes of the Andes, whatever the exposure of the places where 

 they are observed? 



10. Do they occur only at the line of eternal snow, as certain 

 authors maintain, or do the Peruvian and Bolivian Andes furnish veri- 

 fied exceptions to this rule? 



11. Do strangers to the plateaux of the Andes experience the 

 soroche when they reach high elevations on the Cordillera on horse- 

 back? And when they feel the attacks, did muscular efforts usually 

 precede the disturbance of the organs of circulation and respiration? 



12. Do the effects of the soroche differ with age and sex? 



13. Do they vary with idiosyncrasies, and what are the idiosyn- 

 crasies which predispose to it or retard it? 



14. What is the effect exerted upon its production or its symptoms 

 by the seasons, the prevailing winds, or storms? 



15. What is the effect of the cold in the places where the soroche 

 appears? Specify the average temperature of these places and the 

 absolute temperature at the time the symptoms appeared. 



16. What is the effect of dryness or humidity? 



17. Is it proved that the absolute altitude in the atmosphere is 

 not enough to explain certain local anomalies? And if this is an actual 

 fact, seek out the probable causes of these anomalies, either in the 

 atmospheric conditions of the time or the locality, or in the telluric 

 conditions, especially in the nature of emanations which may rise from 

 the ground. Study in this connection the conformation of these lo- 

 calities which might favor the continued presence of water and atmos- 

 pheric humidity, their nearness to ore-bearing regions, which might 

 exhale mineral, harmful, arsenical, or other vapors. Do not neglect 

 occasional conditions in which individuals may be placed. 



18. Does the acclimatization of strangers in relation to the soroche 

 take place more or less quickly, and what are the conditions which 

 favor or delay it? Does this acclimatization have a lasting or merely 

 temporary effect? Do the negroes have more difficulty in becoming 

 acclimatized than the whites? And if the opportunity offers, it would 

 be interesting to make a series of experiments to ascertain the normal 

 pulse rate of the inhabitants of the plateaux, Indians, negroes, and 

 whites; taking care to repeat them on a great number of healthy per- 

 sons of both sexes, adults of verified age, and to make these experi- 

 ments at rest, standing and lying down, at a certain distance from 

 mealtime, and to note the outer temperature of the season, hot or cold. 



19. If the symptoms of the soroche appear in animals, what are 

 their characteristics in the different animals and what are the condi- 



