son in considering the crystallized salt as mere chloride of barium. This, he observes, "may be obtained by heating baryta in chlorine, in which case oxygen is evolved; or more easily by dissolving carbonate of baryta in diluted muriatic acid. By evaporation, tabular crystals are obtained, soluble in five parts of water at 60°; and consisting when dry of 65 barium + 33.5 chlorine 98.5. Its taste is pungent and acrid; when exposed to heat, the water of crystallization separates, and the dry chloride enters into fusion." It is to be observed, that while Mr. Brande admits the existence of water of crystallization in this salt, he neither states its quantity, nor makes any observation as to the effect which it may produce in the theoretic views of the nature of the salt. On referring to the table of equivalents contained in the second volume of the Manual, p. 512, and to that which Mr. Brande has since published in the 14th volume of the Royal Institution Journal, I do not find any mention of muriate of barytes, or of the quantity of water which the crystallized chloride, allowing it to be such, contains. Dr. Ure, in the second edition of his Dictionary, mentions the muriate of barytes as crystallized in tables; and although he calls it a muriate, he states its composition as a chloride, consisting of 4.5 chlorine + 8.75 barium. No mention of muriate of barytes is made by Dr. Henry, in his Elements of Chemistry, excepting under the head of chloride of barium; and like the previously quoted authorities, he appears to consider the crystallized tabular salt as chloride; but does not mention the existence of any water in it. "The dry salt," he observes, "Sir H. Davy considers as a compound of 1 atom of barium 70 + 1 atom of chlorine = 36; hence its representative number is 106, and it consists of Chlorine. 34 66 100 "Muriate of baryta, formed by the action of water on the chloride, must therefore be constituted of 1 atom of muriatic acid 37, + 1 atom of baryta 78, and its equivalent must acid=37, be 115. Hence it should consist, when crystallized, of Acid. = "These numbers do not exactly agree with the experimental results of Aikin and Berzelius, which state its composition as follows: "The analysis, therefore, requires to be attentively repeated." Now I would submit, with great deference, that the analyses which have been already performed are sufficient to clear up the difficulty, which, it appears to me, depends merely upon the mode of viewing the nature of the salt in question. The various metallic chlorides, and the different salts which result from the union of muriatic acid with metallic oxides, may be regarded under several different theoretical points of view: these I shall endeavour to illustrate by considering the barytic chloride and muriate. According to Dr. Thomson's table of equivalents, oxygen being represented by 8, water is 9, chlorine 36, muriatic acid 37, barium 70, and barytes 78; and if we admit for a moment, the existence of what was formerly called dry muriatic acid, its number will be 28. Chloride of barium is then composed of One atom of chlorine. 36 70 106 Supposing, as appears to be the case with muriate of magnesia, that a solution of barytes in muriatic acid could be evaporated to dryness without the formation of water occurring from the decomposition of the acid and oxide, and the union of their hydrogen and oxygen, we should then procure muriate of barytes composed of One atom of muriatic acid. 37 78 115 This compound would also result from the decomposition of one atom of water by an atom of chloride of barium. Considering, according to the opinion formerly adopted by most chemists, and still entertained by Berzelius, that muriatic acid gas is a compound of dry muriatic acid and water, dry muriate of barytes will consist of This number, it will be observed, is that which has already been noticed as representing the chloride. It is a question which, perhaps, scarcely admits of being decided, whether when an oxide, such as that of barium, calcium, or strontium, is dissolved in muriatic acid, and a crystalline salt containing water obtained, such salt be actually a chloride combined with water, or whether one atom of the water suffers decomposition and converts the chloride into a muriate. Supposing, for example, that 115 parts of crystallized muriate of barytes were to lose 9 of water by being heated, that salt before such loss might be regarded as hydrous chloride of barium consisting of 1 atom of chlorine. 36 70 9 115 Or we may consider the 9 parts of water expelled by heat not as previously existing as such, but as arising from the decomposi tion of the muriatic acid and oxide of barium; in which case the salt would be composed of 1 atom of muriatic acid. ... 37 78 115 We find, however, by experiment, that crystallized muriate of barytes loses a larger quantity of water than that above supposed. According to Mr. Aikin (Nicholson's Journal, vol. xxii. p. 312), crystallized muriate of barytes loses from 14.5 to 14.6 per cent. of water, by being heated, a determination which agrees very nearly with Berzelius's statement of 14.8 per cent. If an atom of chloride of barium = 106 were combined in the crystallized salt with 2 atoms of water = 18, then the loss by heat would a little exceed 14.51 per cent. agreeing very nearly with Mr. Aikin's statement. We may, therefore, consider crystallized muriate of barytes as consisting of 1 Or if we consider the salt to exist in the state of muriate, the view of its composition will be: Or lastly, if we adopt the opinion formerly entertained of this salt, and consider it as composed of 1 atom of dry muriate of barytes. 106 or 85.49 The weight of its atom will still be. .... 124 100.00 agreeing very nearly with Aikin, Berzelius, and Dr. Wollaston's memoir. There are but few salts similarly circumstanced with the crystallized muriate of barytes; I shall add the equivalent numbers for crystallized muriate of strontia and muriate of lime. According to Berzelius (Proportions Chimiques, p. 47), muriate of strontia contains 40.53 per cent. of water; the chloride of strontium will therefore be 59-47. Now an atom of chlorine 36, and of strontium 44, will give 80 as the weight of the atom of chloride of strontium, and as 59-47: 40-53 :: 80: 54.52, so little exceeding 54, or 6 atoms of water, that we may consider crystallized muriate of strontia as composed of 1 atom of chloride of strontium 36 + 44 = 80 or 59.7 Weight of atom.... = 54 40.3 134 100.0 Or regarding it as a crystallized muriate of strontia, it will consist of 1 atom of muriate of strontia 37 + 52 = 89 or 66·4 = 45 33.6 134 100.0 Crystallized muriate of lime, according to Berzelius, contains 49-2 per cent. of water; the chloride of calcium remaining will, therefore, amount to 508. An atom of chlorine = 36, and of calcium = 20, the number representing chloride of calcium is 56; and as 50-8: 49.2 :: 56: 54-23, so slightly exceeding 54, that we may regard crystallized muriate of lime as constituted of 1 atom of chloride of calcium 36 + 20 = 56 or 50.9 Weight of atom..... Or, 1 atom of muriate of lime 37 + 28... 5 atoms of water 9 x 5 ... = 54 49.1 ARTICLE IV. On the Deluge. By J. S. Henslow, MA. MGS. FLS. Secretary to the Cambridge Philosophical Society, Professor of Mineralogy in the University of Cambridge. (To the Editor of the Annals of Philosophy.) SIR, Cambridge, Oct. 15, 1823. In a very able article in the 57th number of the Quarterly Review, the "Reliquiæ Diluvianæ," by Prof. Buckland, has been lately examined, and towards the end of that article some observations are made upon the various theories which have been adopted to account for the phenomena of the Deluge. The reviewer is decidedly of opinion that none of the hypotheses hitherto suggested are capable of solving the difficulty, and seems to think that we ought to ascribe the whole to the miraculous interposition of Providence, "excluding the operation of ordinary nature" from our consideration. That God brought the waters, and that God caused them to assuage, is doubtless the language of Scripture; but, as in many other cases, so in the present, I see no reason for supposing that he did not employ the ordinary means of nature as the instruments of his operations. The reviewer himself states his belief that "miraculous agency is often, nay generally, combined with natural means," though he seems at the same time anxious to dispense with them in the present case. The hypothesis which had hitherto appeared the most plausible was one stated by Mr. Greenough, in which it is supposed that the waters of the ocean were thrown into a state of excessive agitation by the near approach of a comet. This hypothesis however, is now clearly shown to be incompatible with the appearances observable in the diluvium of various parts of the earth; and it should also be recollected that the near approach of a comet could not have produced the effect ascribed to its influence by Mr. Greenough, without affording an anomaly in |