Effect of Mountain Air on Man. 191 



ly in front of the shark. We ourselve?, says he, have seen three 

 instances in which the shark was led by the pilot. When the 

 sea-angei (query, devil ?) neared the ship, the pilot swam close to 

 the snout, or near one of the breast-fins of the animal ; some- 

 times he darted rapidly forwards or sidewards, as if looking for 

 something, and constantly went back again to the shark. When 

 we threw overboard a piece of bacon fastened on a great hook, 

 the shark was about twenty paces from the ship. With the 

 quickness of lightning the pilot came up, smelt at the dainty, 

 and instantly swam back again to the shark, swimming many 

 times round his snout, and splashing, as if giving him exact in- 

 formation as to the bacon. Tlie shark now began to put him- 

 self in motion, the pilot showing him the way, and in a moment 

 he was fast upon the hook. Once we watched a pilot for many 

 days who kept constantly swimming close before the keel of the 

 ship. The sailors say, as of a thing well known and familiar, 

 that such a fish, so situated, has lost his shark, and is seeking 

 another. Upon a later occasion, we observed two pilots in sedu- 

 lous attendance on a blue shark, which we caught in the Chinese 

 sea. It seems probable that the pilot feeds on the shark's excre- 

 ment, keep his company for that purpose, and directs his opera- 

 tions solely from this selfish view. 



11. Effect of Mountain Air on Man. — One of the most in- 

 teresting expeditions, says Dr Meyen, was one to the mountains 

 of Peru ; a service of considerable danger, on account of a com- 

 plaint which almost invariably attacks the traveller during the 

 ascent. The symptoms are described as follows : — We were 

 tormented with a burning thirst, which no drink was able to 

 assuage ; a slice of water-melon which we had brought with us 

 was the only thing we could relish, whilst our people ate garlick 

 and drank spirits, maintaining that this was the best way to 

 guard against the effects of the journey. We kept on ascend- 

 ing till two o'clock in the afternoon. We were already near the 

 little ridge which extends W. S. W. from the summit of the 

 mountain (the volcano of Arcquipa), and we could even distin- 

 guish the little stones upon the summit when our strength at 

 once abandoned us, and we were overtaken by the disease 

 sorocco. The nervous feverishness under which we had suffered 

 from the first, had been gradually becoming worse and worse ; 



