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minerals affords forms which are identical with some of the

crystalline forms which are common to both minerals, and this is the case in regard to philipsite and harmotome,—we can hardly maintain the diversity of the two substances, merely because these cleavage-forms may not be identical with one another, if other circumstances tend to establish the connexion of the two bodies.

I shall here, with the view of enabling every one to draw his own conclusion as to the probability of the ultimate reconciliation of the constitution of the two varieties, subjoin Tables containing all the analyses of the mineral with which I am acquainted, and shall annex the composition of both varieties calculated by the atomic weights of Berzelius, according to the chemical formulæ corresponding with KSS + 2 CS? + 10 AS2 + 15 Aq for the lime variety, and 3 BS? + 10 ASP + 15 Aq for the barytic variety. It will be observed that the Strontian mineral approaches nearer the theoretical composition than any of the other barytic varieties, in so far as respects baryta and the other replacing constituents, which is perhaps a step not altogether without importance, towards a more perfect accommodation of the two varieties, although, as respects silica and alumina, some of the other analyses come nearer the formula.

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may take this opportunity of mentioning, that after I had detected alkalies in barytic harmotome, it occurred to me to examine Brewsterite again for alkalies by the same process, which was applied to the former mineral; my previous researches for alkalies in Brewsterite having been made by decomposing it by carbonate of baryta, and throwing down the baryta by carbonate of ammonia, a method which renders necessary the ultimate expulsion by heat of a very large quantity of ammoniacal salt, which is apt to carry along with it small quantities of fixed chlorides. I accordingly treated a small quantity of powdered Brewsterite with muriatic acid, leaving them in contact for some days, and occasionally applying heat. By the process already detailed, I ultimately obtained a minute quantity of cubical crystals ; and, on examining those by muriate of platinum, they seemed to be entirely chloride of sodium, at least operating with the small quantity of materials which I used, I could not detect potash. The minute quantity of soda is of course in addition to strontia, baryta, and the other constituents which I formerly mentioned in Brewsterite. When my time permits, I intend to execute another analysis of the mineral, to ascertain the exact proportion of alkali it contains.

Remarks on some of Baron Cuvier's Lectures on the History

of the Natural Sciences, in reference to the Scientific Knowledge of the Egyptians ; of the source from whence Moses derived his Cosmogony, and the general agreement of that

Cosmogony with Modern Geology *. IN some of the Numbers of the Edinburgh New Philosophical Journal published in 1830, are given Reports of Lectures on the History of the Natural Sciences by Baron Cuvier ; and in pages 342, No. XVI., we find in them the following statement respecting the Hebrew legislator :-“ His books shew us, that he had very perfect ideas respecting several of the highest questions of natural philosophy. His cosmogony especially, considered in a purely scientific view, is extremely remarkable, inasmuch as the order which it assigns to the different epochs of creation, is precisely the same as that which has been deduced from geological considerations." This, then, is the issue, in the opinion of Baron Cuvier, of that science, which has been held by many persons to teach conclusions at variance with the Book of Genesis,—when at last more matured by a series of careful observations and legitimate induction, it teaches us precisely what Moses had taught more than three thousand years ago.

But at the same time that the Baron makes this statement, it is implied by him in the accompanying sentences, that the Hebrew legislator had acquired his knowledge of the cosmogony from the Egyptians; for he says, “ The leaders of the colonies which issued from Egypt possessed, in general, but a small part of the knowledge of which the privileged caste (the priests) was the depositary. They carried with them only the practi- , cal results. The case was different with the Hebrew legislator.

• “ No opinion can be heretical but that which is not true. Truths can never war against each other. I affirm, therefore, that we have nothing to fear from the results of our inquiries, provided they be followed in the laborious but secure road of honest induction. In this way, we may rest assured, we shall never arrive at conclusions opposed to any truth, either physical or moral, from whatsoever source that truth may be derived ; nay, rather that new discoveries will ever lend support and illustration to things which are already known, by giving us a larger insight into the universal harmonies of Nature."-- Professor Sedgwick's Address to the Geological Society, February 19.

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He had been brought up by the Egyptian priests, and knew not only their arts, but also their philosophical doctrines.”

In attempting to discuss the merits of the opinion here implied, we would speak in terms of high respect of the illustrious individual who has promulgated it; for such respect is due to one who, without question, has, in the field of natural science, erected a nobler monument to his own fame than any

other who has appeared since the days of Newton.

The premises from which it is inferred that the Egyptian priests may have possessed such a knowledge of geology as would furnish a foundation for the cosmogony of Moses, are by much too meagre to warrant such a conclusion. The chief of the is indeed found in what Herodotus states regarding the land of the Delta, by depositions from the waters of the Nile. It is said in page 340, “ The Egyptians had very correct ideas on several points in geology; they had well observed the laws of alluvial deposition, and at the present day we account for the formation of the Delta in no other manner than that in which it was accounted for in the days of Herodotus.”

In turning to Herodotus, respecting whom many modern discoveries have proved that he was a faithful chronicler of what he saw, although often absurdly credulous of the reports of others, we find no proof in his relation, that the Egyptians had well observed the laws of alluvial deposition. With respect to the priests, he states, in the passage referred to by the Baron, only that they informed him of two facts ; one, that the greater part of a country, of which he describes the limits, was an addition of land to the Egyptians by the depositions of the Nile; the other, that in the reign of Myris, about nine hundred years before the time of the historian, the land was so low, that if the river rose to the height of eight cubits, it was sufficiently watered; whereas at the time he visited Egypt, unless the river rose fifteen or sixteen cubits the land was not sufficiently watered. This is not science, but history. No reasoning of the priests is added with regard to these simple facts; and the evidence appears conclusive, that he had heard no reasoning of theirs, in this circumstance, that he himself proceeds to reason regarding them with considerable ingenuity, and to prove their high probability from a variety of considerations, and could scarcely have omitted the arguments of the priests had he heard any from them. As far as regards the science contained in this passage of Herodotus, it is perhaps as truly philosophical as any other to be found in his writings; but the philosophy is exclusively that of the Greek himself. The facts, which rested on the authority of the priests, were of a character that it required no science or cultivated understanding to ascertain ; no more, indeed, than, it requires in the present inhabitants of Cairo to discern when the Nile rises sufficiently to secure a pro

ductive crop.

But we are informed also, page 340, that “the properties of minerals were tolerably well examined. The country offered every facility for this; the mountains which form the sides of the valley of the Nile exhibited, and in all their native lustre, various species of rocks ; in the lower part limestone, farther up sandstone, and towards Syene, porphyry and granite.' Egypt was in some measure a great mineralogical cabinet. The neces sity of passing along the small valleys which run towards the Red Sea, led to the discovery of other minerals, which do not occur in so great masses. It was in one of them that the mine of emeralds was discovered, which supplied all those known in antiquity."

The discovery and working of the emerald mines, the only fact stated here, from which any thing can be inferred affecting the present subject, does not necessarily imply that the properties of minerals were tolerably well examined. Very barbarous nations, among whom not a trace of legitimate science has been discovered, have yet the propensity and the skill to dig out and ornament their persons with the natural gems; and it implies no more knowledge of mineralogy, much less of geology, in the ancient Egyptians, to dig mines for the emeralds, than it does in the inhabitants of Pegu to search for the rubies of their country, or in those of Siam for the sapphire. It may be allowed, yet within certain limits, that the properties of minerals were in some degree examined. It appears to have been known to them that their granites and syenites were more durable than their sandstones and limestones, as they have often carried the former from great distances to execute their more important architectural works, when they had the others nearer at hand;

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