MINERALOGY. 361 



but where the labour of irrigation is rf^quired this impost is 

 reduced one-half, in consideration of the additional expense. 

 Of all kinds of grain dhourra is the most productive. On 

 the hills of Yemen it gives a return of 140 ; and in Tehama, 

 where the inhabitants reap three successive crops from the 

 same field in the same year, this increase varies from 200 to 

 400 : an exuberance that appears almost incredible, but 

 which is chiefly owing to their mode of sowing "and their 

 industrious irrigation. As this grain forms the staple arti- 

 cle of food, not only in Arabia, but in other Eastern countries, 

 its extraordinary fertility must be regarded as one of those 

 benevolent arrangements of Providence, whose economy is 

 adapted with such exquisite wisdom to the wants and circvmi- 

 stances of iJian in all climates and in every region of the earth. 



SECTION 11. MINER.1L0GY. 



We have noticed elsewhere, that the mineral treasures 

 ascribed by the ancients to Arabia have almost entirely van- 

 ished ; although the positive and unanimous testimony both 

 of the Greek and Latin authors will not permit us to doubt 

 as to the fact of the wealth formerly drawn from the veins 

 of Yemen. We have the authority of Niebuhr, that the 

 precious metals are not found or known to exist in Arabia,- 

 which has no mines either of gold or silver. The rivulets 

 no longer wash down the yellow grains from the hills ; nor 

 do their sands exhibit any trace of so rich an intermixture. 

 All the gold circulating in that country comes from Abys- 

 sinia or Europe, and is generally received in payment for 

 coffee or other merchandise. When the Imam of Sanaa last 

 century attempted to introduce a gold currency, he was obliged 

 to melt down foreign money (Venetian sequins) for the pur- 

 pose. There are still enthusiasts in alchymy who pretend 

 to know the art of transmuting metals, and imagine them- 

 selves sure of success could they but discover a certain herb, 

 called haschischct cl dab, which gilds the teeth and gives a 

 yellow colour to the flesh of the sheep and goats that eat it. 

 At Beit el Fakih the Danish travellers found two alchymists 

 who had ruined themselves by their researches into the mys- 

 tery of gold-making ; and they mention a philosopher of 

 Loheia, who endeavoured to persuade them that mines of 



Vol. II.— H h 



