March, 1835. 



RED SNOW. 



395 



my pocket-book, and a month afterwards examined with care 

 the pale discoloured patches on the paper. The specimens, 

 when scraped off, were of a spherical form, with a diameter 

 of the thousandth of an inch. The central part consists of a 

 blood-red substance, surrounded by a colourless bark. When 

 living on the snow they are collected in groups, many lying 

 close together; I overlooked, however, the thin couch of 

 gelatinous matter on which they are said to rest.* The dried 

 specimens placed in any fluid, as water, spirits of wine, or 

 dilated sulphuric acid, were acted on in two different ways : 

 sometimes an expansion was caused, at others a contraction. 

 The central part after immersion invariably appeared as a 

 drop of red oily fluid, containing a few most minute granules ; 

 and these probably are the germs of new individuals. 



As I before remarked, the wind on the crest of the Peu- 

 quenes is generally impetuous and very cold. It is said to 

 blow steadily from the westward or Pacific side : a circum- 

 stance which is likewise mentioned by Dr. Gillies.f As 

 these observations apply chiefly to the summer season (when 

 the passes are frequented), we must consider this wind, as 

 an upper and return current. The Peak of TenerifFe, with a 

 less elevation, and situated in lat. 28°, in like manner falls 

 within the return stream. At first it appears rather sur- 

 prising, that the trade-wind along the northern parts of Chile, 

 and on the coast of Peru, should blow in so very southerly 

 a direction as it does ; but when we reflect, that the Cordillera, 

 running in a north and south line, intercepts, like a great wall, 

 the entire depth of the lower atmospheric current, we can 

 easily see, that the trade-wind must be drawn northward, 

 following the line of mountains, towards the equatorial 

 regions, and thus lose part of that easterly movement which 

 it otherwise would have gained from the rotation of the 

 world. At Mendoza, on the eastern foot of the Andes, the 

 climate is said to be subject to long calms, and to frequent 



* Greville's Scottish Cryptogam. Flora, vol. i v., p. 231. 



t Journal of Natural and Geographical Science, August, 1830. 



