EGYPT, AND SYRIA. 41 
five or fix inches, lies conftantly in the more fhallow 
parts. 
The fijrface of the earth, near the lake, partakes more or 
lefs generally of the chara£ter of natron, and, in the parts far- 
theft removed, offers to the foot the flight refiftance of ploughed 
ground after a flight froft. The foil is coarfe fand. The water 
of the lake, on the flighteft evaporation, immediately depofits 
fait. There is a mountain not far from the lakes, where natron 
is found in infulated bodies, near the furface, of a much lighter 
colour than that produced in the lake, and containing a greater 
portion of alkali. This kind more refembles the natron of 
Barbary, and what I have fince obferved in the road to 
Soudan. ^ 
How thick the fubftance of natron commonly Is in the lake, 
I did not accurately determine, but thofe employed to colledl it 
report that it never exceeds a cubit, or common pike ; but it ap- 
pears to be regenerated as it is carried away. The Arabs report 
that the natron country extends twenty days journey ; and in- 
deed I had remarked fomething refembling that fubftance near 
Siwa. I underftood it was delivered at Terane for about a 
piafter the cantor. But there are, probably, fome other ex- 
penfes attending it. Notwithftanding S'^ R.'s exclufive right, 
the Arabs carry off fome of the commodity, which they fell 
wherever they can find a market. The quantity exported to 
Venice was much decreafing in 1792, as it had been found on 
trial inapplicable to many purpofes to which if was fuppofed it 
might be converted. I know not how far correct their expe- 
G riments 
