who will on no account
be seen or spoken to, come in boats to the place where the heaps of salt
are placed, and after laying a sum in gold on each heap as its price,
retire in their turns. After they are gone, the owners of the salt return,
and if the quantity of gold on their heaps is satisfactory to them, they
take it away and leave the salt; if not, they leave both and withdraw
again. In this manner they carry on their traffick, without seeing or
speaking to each other, and this custom is very ancient among them, as
has been affirmed to me for truth by several merchants of the desert,
both Arabs and Azanhaji, and other creditable persons[2].

On inquiring how it came to pass that the emperor of Melli, whom they
represented as a powerful sovereign, did not find means, by friendship or
force, to discover who these people were who would not suffer themselves
to be seen or talked to, I was informed that this emperor, not many years
ago, resolved to procure some of these invisible people, and held a
council on the occasion, in which the following plan was devised and
carried into execution. Before the salt caravan returned the half days
journey from their salt heaps, some of the emperors people made certain
pits by the water side, and near the place where the salt was left, and
when the negroes came to deposit their gold on the salt, those who were
concealed in the pits attacked them suddenly and took four of them
prisoners, all the rest making their escape. Three of those who were thus
taken were immediately set free by the captors, who judged that one would
be quite sufficient to satisfy the curiosity of their emperor, and that
the negroes would be the less offended. But after all, the design proved
abortive; for though spoken to in various languages, the prisoner would
neither speak or take any victuals, and died at the end of four days. On
this account, the Melli negroes concluded that these other negroes were
dumb; but others were of opinion, that being endowed with the human form,
they must necessarily have the power of speech; but, that finding himself
treated in this manner, so contrary to ancient custom, he refused to
speak from indignation. This untoward result was much regretted by the
negroes of Melli, because it prevented them from gratifying the curiosity
of their emperor; who, on being informed of this persons death, was much
dissatisfied, yet asked what manner of men the prisoners were. He was
accordingly i