
NATURAL HISTORY. 223 
of Melinda, downto Cape Gardefan, to Seba, and the 
fouth coaft of the Red Sea, are obliged to put them- 
felves in Motion, and remove to the next fand, in the 
beginning of the rainy feafon: This is not a partial 
emigration ; the inhabitants of all the countries, from 
the mountains of Abyflinia, northward, the confiu- 
ence of the Nile, and Aftaboras, are once ina year, 
obliged to change their abode, and feek protection in 
the jands of Beja. 
The elephant and rhinoceros, which, by reafon of 
their enormous bulk, and the vaft quantity of food 
and water they daily need, cannot fhift to defert and 
dry places, are obliged, in order to refift the zimb, 
to roll themfelves in mud and mire, which, when 
dry, coats them over like armour. 
Of all thofe who have written of thefe countries, 
the prophet Ifarah alone has givea an account of the 
pra 5p or fly, and defcribed the mode of its oppera- 
tion. Ifaiah, chap. vii. ver. 18 and 19. Providence, 
from the: beginning, it would appear, had fixed its 
habitation to one fpecies of foil; which is a. black, 
fat earth, extremely fruitful. And, contemptible as 
it feems, this infect has invariably given law to the 
fettlement of the country: It prohibited, abfolutely, 
thofe inhabitants of the black earth, called Mazaga, 
houfed in caves and mountains, from enjoying the - 
help of labour of any beafts of burden. It deprived 
them of their flefh, and milk, for food; and gave rife, 
to another nation, leading a wandering life, and pre- 
ferving immenfe herds, by conducting them into the 
fands, beyond the limits of the black earth, and 
bringing them back when the danger from this infect 
was over. 
In the plagues brought on Pharaoh, it was by 
means of this infect that God faid he would ferarate 
» his people from the Egyptians. The land of Gofhen, 
the pofieffion of the ifraelites, was a land of pafture, 
not tilled, nor fown, becaufe not overflowed by the 
Nile; but the land overflowed by the Nile was the 
black earth of the valley of Egypt: And it was here 
that God confined the zimb ; for he fays, it fhall be 
a fign of this feparation of the people, which he had 
