It has likewise been conceived, that the concealed C011111111fileati011 is between the Caspian sea and the Gulf of Persia ; and in proof of this it has been alleged, that there were every year seen floating on the water in the vicinity of Ormus, a great quatitity of willow leaves, of which kind of tree, those who make the remark say, that a great abundance grows in the environs of the Caspian, hut none in the interior of Persia. The Tigris, however, it is known, receives a great number of rivers from the quarter of Curdistan and the frontiers of Aledia, in which places this tree is sufficiently frequent. It occurs also about Bagdad, and perhaps also in the more southern part of Persia. And, were they supposed to be con veyed by the Diala, or the little Zarb, these leaves would have a shorter course towards the place of their destina tion than that which is assigned to them.
The phenomena of the Caspian Sea have likewise been ascribed to the quality of the bottom, which con sists not of a thick slime, but of a shell sand, the part; cles of which, touching only' in few points, render it very porous. The whole shore nearly is formed of a similar substance. which, layer upon layer, lies here to the depth of three fathoms. Through this sand, it has been alleged that the water is filtered, and falls into the abyss beneath in the same quantity which flows into the st . In the bay of Emba, it is added, above the river Valk, thr water is not let through, the consequence of which is. that it stag nates in that particular part of the lake. es en the fishes putrefying, and t'le exhalations being extremely no%ious.
It has been observed, that the districts extending in different directions from the Caspian arc s •ndy and saline, and present the same shells that are found in the channel of that sea, but which, at the same time. are of a very elifferent character from those nit t with in the beds of the risers, that did formerly, or do now, run in those parts. Sea salt also occurs in the same ti acts, in beds c 4rcet dt pth, and in such quantity as to prevent all ve ;elation, besides tint of iihtine plants. Salt mar sh( s : another distinguishing feature' hi this quarter ; and, :e,ieraliy, from the appe arallee of the here, the d oi its des ation, a id the nature of the t s h either form Lie constituent parts of tl. j,eva, .it s,il, or pre t therhsels es in a moue 1.ter in or I I it. there seems reason to that t,a, t sea at one - e di reached b. yowl he limits w;L'.in which it is at prese% ewitairied. The c( nclusion to which we are naturally led by these appearances, coin cides, at the same time, with the results of certain his torical notices which have been transmitted to us, as well as with what we know of the determination of an cient geographers respecting the position and the boun daries of this sea. Thus Ptolemy, it is known, gave to it an extent of 231 degrees, from west to east, and made it advance 3° more to the north than it does at present ; and, in the Byzantine historians, we find men tion made of an extensive marsh, that even in the fifth century occupied a large portion of the tract of ground which lies to the north of Caucasus, and between the Caspian sea on the one hand, on the other the Euxine. Hence it appears probable, that in remote times, long prior to the era or our most ancient historical details, the Caspian Sea extended, in a north-west direction, beyond the i\Iantysch and the Sarpa ; towards the north, over all the plains that are watered by the Volga, the Yaik, and the Emba ; that it was united to the lake of Aral ; and that it covered a part of the plains of Great Tartary. These suppositions being admitted, it may,
in connection with them, be allowed, that in the time of Ptolemy the Caspian Sea had an extent somewhat great er than it has at present, though certainly not so great as that which is assigned to it by this geographer ; for it was now separated from the lake of Aral, and had long ceased to have any communication with the sea of Azof. With even the latter of these seas, however, as has been already remarked, some indications of its early junction are still to be found in ancient authors, who both assign to the sea of Azof a greater extent than it now has, and take notice of marshes and lakes to the eastward of it, which have Leen gradually disappearing, but of which the traces arc not even yet entirely lost, and of the origin of which no more plausible account can be given, than that they are the remains of one uniform sheet of water, which at a former period covered all the district of country, of which, as its vestiges and remembrancers, these now occupy such detached portions.* Notwithstanding the early attention which this sea seems to have received, it does not yet appear, that any of the ancient authors that have been named, or others who have left any statements relative to it, succeeded in determining even nearly its true form and extent. It was not apparently even ascertained, whether its greatest length was from north to south, or from east to west. So much, indeed, was this point misunderstood, that, in the ancient maps which illustrate the geography of Ptolemy, it is delineated as if its greatest length extended from cast to west. In modern times, the first considera ble information obtained in Europe concerning the true form of the Caspian, was furnished by Anthony Jenkin son, an English merchant, who, with a caravan from Russia, travelled along a considerable part of its coast in the 3ear 1588. The accuracy of his description was confirmed by an actual survey of that sea, made by order of Peter the Great, A. D. 1'718, when it was found to be, in length about 1100 versts from the mouth of the Ural to the coast of Mazanderan : its greatest width, from the mouth of the Terek to the extremity of the bay of Mertvoi Kultyuk, being 8°, rather more than 700 vcrsts and the measurement in other situations more to the southward varying with the position : in one place it was found to be 6°, or somewhat more than 525 versts ; in another it was 2° 35', or 225 versts. Tile circum ference of the sea, comprehending the great gulfs, but excluding the little sinuosities, is stated at 4180 versts. Whatever may be, in other respects, concluded concern ing the ancient limits of the Caspian, it will at least hardly admit of doubt, that the chain of mountains which branches from the west of the Ural to the north of Oren burg, and reaches to the Volga, must in all ages have restricted it towards the north. In an eastern direction, the elevated level which now presents itself between this sea and the Aral, may have taken its rise from the quan tity of sand rolled down by the Gihon, the Sire, and other rivers that still flow into the latter sea.