But since this kind of metal is plentiful with them, but copper and iron are scarce, they barter these wares with the traders at an equal rate[115].” Strabo probably got his information from Artemidorus, who is his chief authority for everything connected with the Red Sea. Diodorus, whose authority is Agatharchides, substantially agrees with Strabo in all the main facts, such as the name of the tribe who cannot work up the gold-dust, whilst he adds the names of the Alilaeans and Gasandans, which are not given by Strabo[116]. From Arabia we naturally pass on to Egypt. We have already seen that the archaeologists assign reasons for supposing that the Egyptians were acquainted with gold from the remotest ages. The Egyptian word for gold is _nub_, from which the name Nubia, _i.e._ _El Dorado_, is commonly derived. Having fresh in our minds the interesting fact noticed above (p. 69) that the universal word for gold in use amongst the Turko-Tartaric races is probably derived from the Altai, the source from which they first got the metal, we are tempted to reverse the ordinary doctrine, and to derive the Egyptian name for gold from that of the region whence they first obtained it. The principle of naming products after the region or place from which they have been first brought is too well known to need illustration. Instances are familiar in all languages: _Cappadocae_, the Latin name for lettuce; _Persica_ from which has come our _peach_, through the French; Indian corn, india-rubber, etc. are sufficient examples. The negroes of Eastern Africa call a certain kind of cloth _Merikano_, _i.e._ American. Perhaps, then, the name _nub_ is rather a word of this class, and Nubia is not like Gold Coast, which belongs to the category of names formed by epithets applied in consequence of some article already well known having been found there.