36 



RIO DE JANEIRO. 



May— June, 1832. 



I went to the Botanic Garden, where many plants, well 

 known for their great utility, might be seen growing. 

 The leaves of the camphor, pepper, cinnamon, and clove 

 trees were delightfully aromatick ; and the bread fruit, the 

 jack, and the mango, vied with each other in the magni- 

 ficence of their foliage. The landscape in the neighbourhood 

 of Bahia almost takes its character from the two latter trees. 

 Before seeing them, I had no idea that any trees could cast 

 so black a shade on the ground. Both of them bear to the 

 ever green vegetation of these climates, the same kind of rela- 

 tion which laurels and hollies in England do to the lighter 

 green of the deciduous trees. It may be observed, that the 

 houses within the tropics are surrounded by the most beau- 

 tiful 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 struck with a remark of 

 Humboldt^ s, who often alludes to the thin vapour which, 

 without changing the transparency of the air, renders its tints 

 more harmonious, softens its effects," &c. 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 

 greater distance all colours were blended into a most beau- 

 tiful haze, of a pale French gray, mingled with a little blue. 

 The condition of the atmosphere between the morning and 

 about noon, when the effect was most evident, had under- 

 gone little change, excepting in its dryness. In the interval, 

 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 large liliaceous plants, which shaded the stream- 

 lets of clear water. Sitting down on a block of granite, it 

 was delightful to watch the various insects and birds as they 



