ILLUSTRATIONS (41). PLAIN OF ANTISANA. 139 



like light, are now seen to scintillate in the zenith.* All these 

 phenomena are the result of the increased quantity of aqueous 

 vapour floating in the atmosphere. 



(39) p. 16. " The humid clay soil is seen to rise slowly in a 



broad flake" 



Drought produces the same phenomena in animals and 

 plants as the abstraction of heat. During the dry season 

 many tropical plants lose their leaves. The crocodile and 

 other amphibious animals conceal themselves in the mud and 

 lie apparently dead, like animals in cold regions who are 

 thrown into a state of hybernation.f 



(40) p. 17. " A vast inland sea" 



Nowhere are these inundations on a larger scale than in the 

 network of streams formed by the Apure, the Arachuna, 

 the Pajara, the Arauca, and the Cabuliare. Large vessels 

 sail across the country over the Steppe for 40 or 50 miles. 



(41) p. 17. " To the mountainous plain of Antisana." 

 The great mountain plateau which surrounds the volcano 

 of Antisana is 13,473 feet above the level of the sea. The 

 pressure of the atmosphere is so inconsiderable at this height, 

 that blood will flow from the nostrils and mouth of the wild 

 bull when hunted with dogs. 



(42) p. 17. " The marshy waters of B era and Rastro" 

 I have elsewhere more circumstantially described the 

 capture of the gymnotus4 Mons. Gay Lussac and myself 

 were perfectly successful in the experiments we conducted 

 without a chain on a living gymnotus, which was still very 

 vigorous when it reached Paris. The discharge of electricity 

 is entirely dependent on the will of the animal. We did not 

 observe any electric sparks, but other physicists have done so 

 on numerous occasions. 



(43) p. 18. "Awakened by the contact of moist and dissimidar 



particles" 

 In all organic bodies dissimilar substances come into 



* Compare Arago in my Relation hist., t. i. p. 623. 

 t See my Relat. histor., t, ii. pp. 196, 626. 



t Observations de Zoologie et < Anatomic comparee,i. \. pp. 83-87, 

 and Rttat. hist., t. ii. pp. 173-190. 



