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covered immense muddy lakes. Now, the inner part of the Bay at low 

 water has the appearance of an enormous bank, of a black and repug- 

 nant colour. 



Formerly that most extensive border of trees, embracing an area of 

 many square kilometres formed a real martime forest of trees, in which 

 predominated tannin ; and which, directly and indirectly, fostered the 

 life of prodigious quantities of fish and shell-fish, and every species of 

 inhabitant of the sea. 



This tree is the mangrove ('mangue') It is a vegetable that spreads 

 over the place in which it is planted, and is, for many reasons, 

 marvellous. It solidifies the mud where it vegetates, and raises it ; for 

 every thing that adheres to the aforesaid trees held by its shoots, which 

 are on a level with its roots, and by a thin and consistent vegetation, 

 which has the appearance of asparagus, and which the trees throw out # 



From the leaves, bark, and seeds which fall from the mangrove the 

 mud used to receive an immense amount of tannin, a powerful 

 antidote against putrefaction. Solidifying the superficies of the mud by 

 the astringent nature that characterises it, the precious shrub prevented 

 the spreading of the mud, and at the same time rendered difficult the 

 procreation of the immovable shell-fish, and consequently facilitated 

 that of the others. I refer to the crabs, which were the greatest con- 

 sumers of organic remains or matter deposited on the banks. This 

 most useful tree did not cease in its work of conquest over the water. 

 It advanced day by day, hour by hour, sinking its roots, gaining on the 

 resistance of the mud, raising it higher, and converting it little b y 

 little into solid ground. If, in consequence of bad weather, a portion of 

 the mud was brought to join the area conquered, the untiring workman 

 was not long in covering it and making it wholesome ; if a part of the 

 conquest was torn away by the current, the pertinacious roots did not 

 remain long without material to fix upon." 



If the mangue had been preserved, it would tend to raise up the im- 

 mersed part of the borders of the Bay and Islands, and thus, limiting 

 the space over which the waters extend, would give them greater depth. 



At the same time that the mud swamps of the majestic bay were covered 

 with the spontaneous growth of this tree (mangue), yellow fever was 

 unknown among us, as were other disorders of an epidemic character, 

 the breaking out of which it would be erroneous to impute to the in- 

 crease of the population. * * * 



The aspect of every thing has changed. The population of Bio de 

 Janeiro, as well as that of Nictheroy and the sea coast, has increased con- 

 siderably during the last 40 to 50 years ; navigation has become develop- 

 ed, numerous industries have also become developed, the necessities of 

 living have also multiplied. Up to a certain period of time, nature was 

 sufficient of itself to repair the damage caused by the destruction of the 

 marine forest ; spontaneous nature was more than sufficient to recoup the 

 damage caused by using the vegetable as combustible. This damage was 

 very small ; and the number of trees, whose power of reproduction is 

 known to be prodigious, is incalculable. The new industries, in great 

 want of cheap and easily obtained combustible, deeply disturbed by des- 

 truction that spontaneous gift of nature. * * * 



The quantity of tannin that our waters failed to receive is incalculable. 



