OF SEVERAL PARTS OF WESTERN ASIA. 409 



I shall now give a more detailed account of the geology of the 

 countiy around Oroomiah, so far as I am able to do it, from the 

 specimens and descriptions furnished by IVIr. Perkins. 



" The plain of Oroomiah," says IVIr. Perkins, " is about forty 

 miles in length, as it lies vipon the lake, and it extends back to the 

 Koordish mountains, a high range of which, sweeping around in a 

 semicircular direction, its two extremities reaching the water's 

 edge, encloses the plain hke a vast amphitheatre. This plain, at its 

 widest point, where it swells a few miles into the lake, as well as 

 retreats back into the curve of the mountain range, is about twenty 

 miles broad. Its appearance from the heights back of it, is that of 

 a perfect level : so much so, that the beholder can hardly resist the 

 idea that it is a bed of tide waters, which is just laid bare by their 

 ebb, and is soon to be enveloped by a returning flow. In fact, how- 

 ever, there is a considerable descent from the mountain side of the 

 plain to the lake : and the three considerable rivers, (each from one 

 hundred to two hundred feet wide,) which roll down through rug- 

 ged ravines in the mountain range, flow across the plain and pour 

 themselves into the lake with rapid currents. I am not aware, that 

 the lake ever does overflow more than a mile or two of the shore, 

 even in the spring, and it has no tides." 



" The plain of Oroomiah, in reality as well as in appearance, is 

 extremely fertile. With the adjacent declivities of the mountains, 

 comprising an area of about six hundred square miles, it sustains 

 three hundred and fifty villages ; almost eveiy inch of the soil being 

 under cultivation. Its almost entire and frequent irrigation, by 

 means of small canals from the rivers, and the immense annual 

 growth and decay of vegetation, are the secret of the unhealthiness 

 of our climate." 



That the causes here suggested by Mr. Perkins are among the 

 sources whence disease originates on the plain of Oroomiah, I 

 do not doubt ; but I must be allowed to suggest, as other causes, 

 the great quantity of sulphurated hydi'ogen generated by the 

 lake, and of carbonic acid from the mineral springs in the vicin- 

 ity. These two gases, I believe, are now generally regarded as 

 among the most pernicious of miasms. Not improbably these 

 gases are produced from the soil of that region, especially in low 

 and damp places, as well as from the lake. Alkalies or lime- 



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