346 GENERAL OBSERVATIONS. 
which amounts to the same thing, its communication with 
Wangara, should be disputed, Captain Tuckey’s hypothe- 
sis of its issuing from some other great lake, to the north- 
ward of the line, will still retain its probability. The idea 
of a lake seems to have arisen from the ‘ extraordinary 
quiet rise” of the river, which was from three to six inches 
in twenty four hours. If the rise of the Zaire had pro- 
ceeded from rains to the southward of the line, swelling 
the tributary streams, and pouring, im mountain torrents, the 
waters into the main channel, the rise would have been 
sudden and impetuous; but coming on as it did in a quiet 
and regular manner, it could proceed only from the gradual 
overflowing of a lake. 
There is, however, another circumstance in favour of a 
river issuing from Wangara, or the lakes and swamps de- 
signated under that name, and of that river being the Zaire. 
There is not a lake, perhaps, of any magnitude in the 
known world, without an outlet, whose waters are not 
saline—the Caspian, the Aral and the neghbouring lakes, 
the Asphaltites or Dead Sea, and all those of Asia, which 
have no outlet, are salt.* If therefore the lakes of Wangara 
had no outlet, but all the waters received into them spread 
themselves over an extended surface during the rains, and 
were evaporated in the dry season, there would necessarily 
be deposited on the earth, so left dry, an incrustation of salt, 
and the remaining water would be strongly impregnated with 
* The freshness of the Zuré or Zurrah, the Aria Palus, in Seistan, rests on no 
authority—but if so, its waters are not evaporated, but pass off by filtration 
through the sand. 
