Mr R. Adie’s Account of Electrical Experiments. 97 
In northern Africa, the terms Sade/ and Sahara are also ap- 
plied to great flat spaces, whose distinction depends on their 
constituent elements, which are sandy and moving in the for- 
mer, and pebbly or stony (as in the plain of the Crau in the 
south of France), in the latter. Nevertheless, the meaning of 
these expressions varies: thus the sahel is also a district swept 
by the wind, or the shore of the sea; and the sahara, a place 
exposed to the sun: lastly, the sahara is used to designate a 
desert where nothing grows, or, on the contrary, a desert 
with pastures. Some epithets are likewise employed to ex- 
press local peculiarities ; thus sahara-bila-ma, and sahara-ul- 
aski, mean the desert without water, and the complete desert. 
As to more circumscribed spaces, if their nakedness is com- 
plete, they receive the name of ozacad ; if they present some 
dry herbs, they are termed azgar ; and, lastly, if a moderate 
temperature prevails, they are designated by the name of 
hair. 
A plateau is expressed among the Persians by the name 
of pesichi-refi, and among the Arabians by that of dacca; 
lastly, in northern Africa, mountainous and rugged regions, 
entirely bare, or with valleys covered by vegetation, receive 
the name of harusch ; the garrigues of Languedoc sometimes 
convey an idea of their nature.* 
An Account of Electrical Experiments. By Mr R. ADIn, 
Liverpool. (Communicated by the Author.) 
In the following experiments my object is, through them, to give 
evidence to shew, that the arrangement commonly called the water 
battery, depends for its action on the formation of a metallic oxide ; 
that this oxide is formed from the oxygen of our atmosphere, and 
not from decomposed water; that the action of the battery ceases 
when the atmosphere is shut off from it; and that the electro- 
motive force of the currents derived from the water battery, and 
from the ordinary acid battery, are nearly the same, although in 
* From the Annales de Chimie et de Physique for May and June 1844. 
VOL. XXXVIIL NO. LXXV.—JAN. 1845. G 
