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floating in the water,--one said " like a house," another," like an island,"—to which the Arabs swam off, and cut it up with axes, and gathered enough to sell for more than 500 Spanish dollars. In both cases, the asphaltum was found in the southern part of the Sea. One Sheikh, a man fifty years old, who had spent his life here, said he had never seen asphaltum, or known of its being found, at any other time. The Arabs all supposed, that it collects upon the rocks of the eastern shore, and being broken off, falls into the Sea ; but they did not agree as to the place where this was supposed to occur.

In view of these facts, which were observed or collected by ourselves upon the spot, I would respectfully suggest the following inquiries:

1. May we perhaps regard the lake as having anciently extended no further south than the peninsula ; near which there were the asphaltum-pits, and further south the fertile well-watered plain ?

2. Is it allowable to suppose, that either by a conflagration of the asphaltum in the pits, or by some volcanic action, the soil of this plain (with the cities) might be destroyed, and its level lowered; so that the waters of the lake would rush in, and thus form the present southern bay? Might perhaps the asphaltum have previously collected into a mass or stratum round about the pits, and have become so covered or mixed with soil, as to form a fertile tract, which was then destroyed by conflagration ? Or further, might we perhaps conceive, that in combination with some such cause, the bottom of the sea might be heaved up by volcanic action, so as to raise the level of the waters, and cause them to overflow a large tract?

3. Is there perhaps good reason for supposing, that these pits or fountains of asphaltum may still exist under the waters of the lake; and that the asphaltum, becoming hard through the action or contact of the water, remains fixed in the orifices of the fountains until dislodged by some shock like that of an earthquake? If, as is reported, asphaltum were anciently more abundant in the lake than at present, this might perhaps be accounted for, by supposing it not to have been usually gathered and carried away.

I might go on and suggest many other inquiries ; but these perhaps are sufficient for the purpose in view. For any suggestions which you may make relative to these or other kindred topics, I shall feel myself under the most grateful obligations. With high consideration,

Yours, etc. (Signed)

E. ROBINSON. P. S. I forgot to say that small lumps of sulphur are found in many places along the shores of the sea.

II. M. Von Buch to Prof. E. Robinson.*

Berlin, 20th April, 1839. MONSIEUR,

C'est plutôt pour répondre à l'honorable confiance que vous voulez avoir en moi, que dans l'espérance de pouvoir vous faire une observation digne de vous être répresentée, que je vous adresse ces lignes.

La vallée du Jourdain est une crevasse, qui s'étend depuis le Liban jusqu'à la Mer Rouge sans interruption. Voilà, à ce qui me semble, le resultat de vos récherches comme de celles de M. le Comte Bertou et M. Callier, qui malgré ce fait en veulent à M. Ritter pour avoir dit la même chose. Ces longues crévasses, fréquentes surtout dans les montagnes calcaires, donnent la configuration à nos continents. Si elles sont très larges et profondes, elles donnent

* For the convenience of such of our readers as may not understand the French language, we give below a translation of this letter of M. de Buch. (Ed.

Translation.

SIR,

It is rather with a view of responding to the confidence with which you are pleased to honor me, than under the expectation of being able to present you any observations worthy of your attention, that I transmit you these lines.

The valley of the Jordan is a fissure, extending uninterruptedly from the Libanus to the Red Sea. This is the result to which your own investigations lead, as do also those of Count Bertou and Mr. Ritter, who notwithstanding found fault with Mr. Callier for having affirmed the same thing. These long fissures, which are of frequent occurrence, especially amongst calcareous mountains, give rise to the configuration of our continents. When of great size and depth, they afford passage aux montagnes primitives, qui par celle raison for. inent des chaines, dans une direction, que la crévasse leur a préscrite. On peut donc s'attendre à un plus grand developpement des agens volcaniques au fond de cette crévasse, que sur les hauteurs.

Le sel gemme est, d'après les recherches les plus récentes, un produit d'une action volcanique ou plutanique le long d'une ouverture de cette nature. Mais, les sources d' asphalte ou de bitume le sont aussi ; comme le prouvent la quantit de sources de bitume depuis le pied du Zagros aux environs de Bassorah jusqu'à Mosul et à Bakou; comme le prouvent encore le source de bitume dans le golfe de Naples, ou à Mellitti près de Siracuse ; comme le prouvent les sources de bitume sur l'isle de Zante, et même le bitume de Seyssel dont on fait les trottoirs à Paris.

L'Asphalte de la Mer Morte n'est vrais-semblablement que le bitume consolidé au fond du lac, qui ne peut pas s'écouler, et forme par conséquent une couche sur ce fond, comme à l'isle de Trinidad. Il est assez vrais-semblable, que celle accumulation se soit faite dans les temps reculés, comme de nos jours ; et si des actions volcaniques, une elevation du terrain, et des tremblements de terre ont mis au jour des

egress to the primitive mountains, which accordingly form chains in the direction prescribed to them by the fissure. We may therefore look for a greater development of volcanic agencies at the bottom of such fissures than on the highlands.

Fossil salt, according to the most recent researches, is a product of volcanic or plutonic action along an opening of this description. That springs of asphaltum or bitumen, however, originate in the same manner, is proved by the number of them which exist in the tract of country extending from the foot of the Zagrus in the neighborhood of Bassora as far as Mosul, and at Bakou, by the one in the bay of Naples and at Melliti near Syracuse, and also by those of Zante; to which may be added the bitumen of Seyssel, of which the footpaths of Paris are constructed.

The asphaltum of the Dead Sea is probably nothing more than the bitumen consolidated at the bottom of the lake, which being unable to flow off, forms there a bed, as is the case in the island of Trinidad. It is altogether probable that this accumulation took place in ancient times as in our own day; and if volcanic actions, the upheaving of the soil, and earthquakes, have brought to light, masses of asphaltum analogous masses d'asphalte analogues à celles que vous avez decrite (phénomène de la plus haute importance, inconnue jusqu'ici,) on peut très bien concevoir la conflagration de cités entières par l'inflammation de matières si éminément combustibles.

Si on pouvait decouvrir quelque masse, basaltique dans la partie ou méridionale ou vers l'extremité sud de la Mer Morte, on pouvait croire, qu’un “dyke” basaltique se soit fait jour lors de la celébre catastrophe, comme cela est arrivé en 1820 près de l'isle de Banda et au pied du volcan de Ternate, (Descript. Phys. des Isles Banians, p. 412.) Les mouvements qui accompagnent la sortie d'un tel “dyke” sont bien en état de produire tous les phénomènes qui ont changé cette contrée interressante, sans éxercer une influence très marquée sur la forme et la configuration des montagnes à l'entour.

La fertilité du sel dépend quelquefois de très légers accidents. Il n'est pas probable que le bitume soit propre pours l'augmenter. Mais il est bien possible, que les mouvements du terrain ont pu mettre au jour une plus grande masse de sel gemme, entrainée

par les eaux vers le fond de la vallée ; ce qui suffisait pour lui ôter sa productibilité. Le sel gemme n'aurait pas tant frappé Lot, pour l'imaginer que sa femme eut été changée en sel, si l'on avait eu connaissance de son

to

nose you have described (a phenomenon of the highest importance and hitherto unknown), we can easily conceive the conflagration of entire cities in consequence of the taking fire of materials so excessively combustible.

If a mass of basalt could be discovered in the southern part or towards the southern extremity of the Dead Sea, we might suppose that a basaltic dyke had made its appearance at the celebrated catastrophe, as occurred in 1820 near the island of Banda and also at the foot of the volcano of Ternati, The movements attending the eruption of such a dyke would be well calculated to produce all the phenomena which have changed the face of this interesting country, without exercising a very marked influence on the figure and conformation of the surrounding mountains.

The fertility of the soil sometimes depends on very trifling circumstances. It is not probable that bitumen is calculated to augment it; but it is very possible that the movements of the earth may have expelled a greater mass of fossil salt, afterwards drawn by the water towards the bottom of the valley, which would suffice to destroy its productiveness. The fossil salt would not so have struck Lot as to make him existence entre les couches de la montagne avant le catastrophe mémorable.

Il faut espérer que la Societé Géologique de Londres, si active, voudra hien un jour envoyer un de ses membres pour éclairer avec le flambeau de la Géologie des faits qui intéressent tout le monde. Mais il faudrait recherchier toute la constitution géologique et du Liban et de toute la vallée du Jourdain depuis Tiberias jusqu'a Akaba.

Je conçois, Monsieur, que tout ceci doit peu vous contenter. Mais je pense qu'il est témeraire de se faire une théorie sur des faits dont on n'a pas du moins observé soimême les résultats. J'ai l'honneur d'être avec la plus haute consideration,

Monsieur,

votre tres humble et obeissant, (Signé :) LEOPOLD DE BUCH.

III. Extract from the Work: Description des Isles Canaries

etc. par L. de Buch. P. 412. Paris, 1836.* L'isle de Banda avait auparavant une grande baie sur la côte occidentale : en 1820, après que l'eruption se fut terminée, il se fit dans la mer un soulèvement; et une masse solide,

imagine that his wife had been turned into salt, if its existence between the strata of the mountains had been known previous to the memorable catastrophe.

It is to be hoped that the Geological Society of London, which is so active in its exertions, will one day send one of its members to illuminate with the torch of geology facts that are interesting to all the world. In so doing it would be necessary to investigate the geological structure of the Libanus and of the entire valley of the Jordan from Tiberias to Akaba.

I suspect, sir, that this will prove to you far from satisfactory; but I consider it rash to form a theory on facts of which one has not been able at least to observe for one's self the results.

I have the honor to be, etc., (Signed)

LEOPOLD DE Buch.

• Translation.

The island of Banda had formerly a large bay on its eastern side. In 1820, when the eruption was at an end, the sea became agitated, and there arose a solid mass composed of large blocks

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