terwards I had an attack of it,
though only of a few hours' duration. The veta is felt with great
severity in some districts of the Cordillera, whilst in others, where
the altitude is greater, the disorder is scarcely perceptible. Thus it
would seem that the malady is not caused by diminished atmospheric
pressure, but is dependent on some unknown climatic circumstances. The
districts in which the veta prevails with greatest intensity are, for
the most part, rich in the production of metals, a circumstance which
has given rise to the idea that it is caused by metallic exhalations.

I have already described the effect of the Puna climate on beasts of
burthen. Its influence on some of the domestic animals is no less severe
than on the human race. To cats, it is very fatal, and at the elevation
of 13,000 feet above the sea those animals cannot live. Numerous trials
have been made to rear them in the villages of the upper mountains, but
without effect; for after a few days' abode in those regions, the
animals die in frightful convulsions; but when in this state they do not
attempt to bite. I had two good opportunities of observing the disease
at Yauli. Cats attacked in this way are called, by the natives,
_azorochados_, and antimony is alleged to be the cause of the distemper.
Dogs are also liable to it, but it visits them less severely than cats,
and with care they may be recovered.

Another scourge of the traveller in the Cordillera, is the disease
called the _Surumpe_. It is a violent inflammation of the eyes, caused
by the sudden reflection of the bright rays of the sun on the snow. By
the rarefied air and the cutting wind, the eyes, being kept in a
constant state of irritation, are thereby rendered very susceptible to
the effects of the glaring light. In these regions the sky is often
for a time completely overshadowed by snow clouds, and the greenish
yellow of the plain is soon covered by a sheet of snow: then suddenly
the sun's rays burst through the breaking clouds, and the eyes,
unprepared for the dazzling glare, are almost blinded. A sharp burning
pain is immediately felt, and it speedily increases to an intolerable
degree. The eyes become violently inflamed, and the lids swell and
bleed. The pain of the surumpe is the most intense that can be
imagined, and frequently brings on delirium. The sensation resembles
that which it may be imagined would be felt if cayenne pepper or
gunpowder were rubbed into the eyes. Ch