The mules would halt every fifty yards, and after resting for a few seconds the poor willing animals started of their own accord again.

The short breathing from the rarefied atmosphere is called by the Chilenos "puna;" and they have most ridiculous notions concerning its origin.

Some say "All the waters here have puna;" others that "where there is snow there is puna;"-- and this no doubt is true.

The only sensation I experienced was a slight tightness across the head and chest, like that felt on leaving a warm room and running quickly in frosty weather.

There was some imagination even in this; for upon finding fossil shells on the highest ridge, I entirely forgot the puna in my delight.