24 ASPECTS OF TROPICAL NATURE 



side. Cold winds from the icy Cordillera sweep almost con- 

 stantly over their surface, and during four months of the year 

 they are daily visited by fearful storms. The suddenly dark- 

 ened sky discharges, under terrific thunder and lightning, 

 enormous masses of snow, until the sun breaks forth again. 

 But soon the clouds obsciure its brilliancy ; and thus cold and 

 warmth, winter and summer, here reign alternately, — not, as 

 in our temperate climes, during several months, but within the 

 short space of a single day. 



In a few hours the change of temperature often amounts to 

 forty or forty-five degrees, and the sudden fall of the ther- 

 mometer is rendered still more disagreeable to the traveller by 

 biting winds, which so violently irritate the skin of the hands 

 and face, that it springs open and bleeds from every fissure. 

 An intolerable burning and swelling accompany these wounds, 

 so as to prevent the use of the hands for several days. On the 

 lips it is also very disagreeable, as the pain increases by eating 

 and speaking; and an incautious laugh produces deep rents, 

 which bleed for a long time and heal with difficulty. 



This evil, which is called Chunu by the Peruvian Indians, is 

 also very painful on the eyelids ; but it becomes absolutely in- 

 supportable by the addition of the Sururtipef a very acute and 

 violent inflammation of the eyes, caused by the sun's reflection 

 from the snow. In consequence of the rarefied air and the 

 biting winds, the visual organs are constantly in a state of irrita- 

 tion, which renders them far more sensitive to any strong light 

 than would be the case in a more congenial atmosphere. The 

 rapid change from a clouded sky to the' brilliancy of a ^i^ny 

 snow-field, causes a painful stinging and burning, which^n- 

 creases from minute to minute to such a degree, that even the 

 stoical Indian, when afflicted with this evil, will sit down on the 

 road-side and utter cries of anguish and despair. Chronical 

 ophthalmia, suppuration of the eyelids, and total blindness, are 

 the frequent consequences of an intense Surumpe, against which 

 the traveller over the high lands carefully guards himself by 

 green spectacles or a dark veil. 



A third plague of the wanderer in the Puna is the Veta, 

 which is occasioned by the great rarefaction of the air. Its 

 first symptoms, which generally appear at an elevation of 

 12,000 feet, consist in giddiness, buzzing in the ear, headache, 



