40 EIO BE JANEIRO. 



had no idea that any trees could cast so black a 

 shade on the ground. Both of them bear to the 

 evergreen vegetation of these climates the same 

 kind of relation which laurels and hollies in Eng- 

 land do to the lighter green of the deciduous trees. 

 It may be observed, that the houses within the 

 tropics are surrounded by the most beautiful forms 

 of vegetation, because many of them are at the 

 same time most useful to man. Who can doubt 

 that these qualities are united in the banana, the 

 cocoa-nut, the many kinds of palm, the orange, and 

 the bread-fruit tree ] 



During this day I was particularly sti-uck with 

 a remark of Humboldt's, who often alludes to " the 

 thin vapour which, without changing the transpa- 

 rency of the air, renders its tints more harmonious, 

 and softens its effects." This is an appearance 

 which I have never observed in the temperate 

 zones. The atmosphere, seen through a short space 

 of half or three quarters of a mile, was perfectly 

 lucid, but at a gi'eater distance all colours were 

 blended into a most beautiful haze, of a pale 

 French grey, mingled with a little blue. The con- 

 dition of the atmosphere between the morning and 

 about noon, when the effect was most evident, had 

 undergone little change, excepting in its dryness. 

 In the inten^al, the difference between the dew 

 point and temperature had increased from 7°-5 to 

 17°. 



On another occasion I started early and walked 

 to the Gavia, or topsail mountain. The air was 

 delightfully cool and fragrant ; and the drops of 

 dew still glittered on the leaves of the lai'ge lilia- 

 ceous plants, which shaded the streamlets of clear 

 water. Sitting down on a block of granite, it was 

 delightful to watch the various insects and birds as 

 they flew past. The humming-bird seems particu- 



