INTERIOR Of AFRICA. Sy 
a,s I frequently and painfully experienced in the course of my 
journey. Considerable quantities of this article, however, are 
also supplied to the inland natives by the Moors ; who obtain it 
from the salt-pits in the Great Desart, and receive in return 
corn, cotton cloth, and slaves. 
In thus bartering one commodity for another, many incon- 
veniences must necessarily have arisen at first from the want 
of coined money, or some other visible and determinate me- 
dium, to settle the balance, or difference of value, between dif- 
ferent articles ; to remedy which, the natives of the interior 
make use of small shells called kozvries, as will be shewn here- 
after. On the Coast, the inhabitants have adopted a practice 
which I believe is peculiar to themselves. 
In their early intercourse with Europeans, the article that at- 
tracted most notice was iron. Its utility, in forming the instru- 
ments of war and husbandry, made it preferable to all others ; 
and iron soon became tlie measure by which the value of all 
otiier commodities was ascertained. Thus a certain quantity of 
goods of whatever denomination, appearing to be equal in value 
to a bar of iron, constituted, in the trader's phraseology, a bar 
of that particular merchandize. Twenty leaves of tobacco, for 
instance, were considered as a bar of tobacco ; and a gallon of 
spirits (or rather half spirits and half water), as a bar of rum ; 
a bar of one commodity being reckoned equal in value to a bar 
of another commodity. 
As, however, it must unavoidably happen, that according to 
the plenty or scarcity of goods at market in proportion to the 
demand, the relative value would be subject to continual fiuc- 
E 2 
