Real Cause of the Depreciation of the National Currency explained, &c." 7. "An Exposé of the present Ruinous System of Town and Country Banks, and a Sketch of a Plan for an Establishment of District Banks. By a British Merchant." We have here five vigorous assailants, and only one solitary defender of the Bank Note System.

Yet the very different grounds taken by the assailants, obviously prove that the question is by no means settled in the opinion of the public, notwithstanding that it has been at least temporarily settled in parliament, by the rejection of Mr. Horner's resolutions upon the " Report of the Bullion Committee."

CHAPTER

and Romances.

W

E have received the first and second parts of the Philosophical Transactions for the current year; and the articles of which they consist are the six following:I." The Crooninian Lecture, by W.Hyde Wollaston, M. D. Sec. R. S." This is a more desultory and unconnected, and in many respects a less elaborate paper than has lately been presented to the world under the title it bears. "I am aware," observes Dr. W. " that the remarks which I have to offer on the present occasion, may be thought to bear too little direct relation to each other for insertion in the same lecture; yet any observation respect ing the mode of action of voluntary muscles, and every inquiry into the causes which derange, and into the means of assisting the action of the heart and blood vessels, must be allowed to promote the design of Dr. Croone, who instituted these annual disquisitions." And, accordingly, the writer proceeds to discuss three distinct subjects connected with his general survey; and of these the lecture before us consists: part 1, being" on the duration of muscular motion:" part 2, " on sea-sickness" part 3, 68 on the salutary effects of riding, and other modes of gestation." The observations are neatly drawn up; but we do not perceive any thing of peculiar novelty or importance to detain us by a detailed examination of

1910.

them. "The Bakerian Lecture for 1809, on some new electrochemical researches on various objects, particularly the metallic bodies, from the alkalies and earths, and on some combinations of hydrogen. By Humphry Davy, Esq." This paper is divided into five sections: the first is a brief introduction: the second contains "some new experi ments on the metals from the fixed alkalies;" the chief object of which is to confirm the author's theory in respect to potasium and sodium, as being simple substances in opposition to that of M. M. Gay Lusac and Thenard, who have asserted them to be compounds of their respective alkalies and of hydrogen. This assertion Mr. Davy shortly noticed in his paper on the same subject, introduced into the volume of the Philosophical Transactions for the preceding year; he returns to it more in detail in the section before us, and if he do not sufficiently establish his first doctrine, he completely refutes that of his antagonists. The third section contains " tains Experiments on nitrogen ammonia, and the amalgam from ammonia." These are very far from being decisive; and, to a certain extent, seem rather to bring us back to the old idea that nitrogen is a simple elementary substance, than a compound either of oxygen or of hydrogen. Section four, is " on the metals of earths." The experi

ments here detailed, so far as they go, advance the doctrine of the metallic origin of the earths, but they only advance it. The fifth section is entitled "Some Considerations of Theory illustrated by new facts." The general object aimed at by these observations is the establishment of the doctrine, that "hydrogen is a protoxyd of ainmonium, ammonia a deutoxyd, and nitrogen a tritoxyd of the same metal," by which means "the theory of che mistry would attain a happy simplicity, and the existing arguments would harmonize with all the new facts." Upon the whole we here meet with another retrograde march towards the antiphlogistic theory, hydrogen being here considered, or at least hinted at, as the principle of inflammability, as well as the cause of metallization.

Whilst we are upon the subject of the electrochemical experiments of Mr. Davy, we shall step forward to article XIV., in which we meet with another and still more important paper upon the same subject.. It is entitled " Researches on the Muriatic Acid, its nature and combinations; and on the Elements of the Muriatic Acid. With some experiments on sulphur and phosphorus, made in the laboratory of the Royal Institution." When Scheele produced his wonderful discovery of the oxymuriatic acid, he considered it as muriatic acid freed from hydrogen; and regarded common muriatic acid as a compound of hydrogen and oxymuriatic acid: and on this theory, he denominated oxymuriatic acid, dephlogisticated muriatic acid, hydrogen being the phlogiston of this acute and indefatigable chemist. M. Berthollet, a few years after the discovery of Scheele, made a number of important and curious experiments on this

body; and concluded that it was composed of muriatic gass and oxygen; hence arose the name it bears at present, and the doctrine which for the last twenty years has been almost universally adopted. Dr. Henry, in an elaborate series of experiments, made with the view of decomposing muriatic acid gass ascertained that hydrogen was produced from it by electricity; but he ascribed it to the water contained in the gass. The general tendency of the very valuable paper before us, is to re-establish the original theory of Scheele in opposition to that of the French chemists. We cannot copy the experiments referred to, nor even the general chain of reasoning that accompanies them; but shall briefly remark in the words of Mr. Davy himself, that " it is evident from this series of observations that Scheele's view (though obscured by terms derived from a vague and unfounded general theory) of the nature of the oxymuriatic and muriatic acids, may be considered as an expression of facts whilst the view adopted by the French school of chemisty, and which, till it is minutely examined, appears so beautiful and satisfactory, rests, in the present state of our knowledge, upon hypothetical grounds."-"Few substances have less claim to be considered as an acid than oxymuriatic acid. As yet we have no right to say that it has been decompounded: and as its tendency of combination is with pure inflammable matters, it may possibly belong to the same bodies as oxygen. May it not in fact be a peculiar acidifying and dissolving principle, forming compounds with combustible bodies, analogous to acids containing oxygen, or oxyds, in their properties and powers of combination; but differing from

them

them in being for the most part decomposable by water? On this idea muriatic acid may be considered as baving hydrogen for its basis, and oxymuriatic acid for its acidifying principle. And the phosphoric sublimate as having phosphorus for its basis, and oxymuriatic acid for its acidifying matter. It evinces an approach, or rather a similarity towards oxygen in thus possessing an acidifying power; and in its flying off when electrized, in the Voltaic circuit, at the positive surface, at least when a solution of oxymuriatic acid in water was the substance experimented upon. It differs wonderfully, however, from the properties of oxygen in the curious fact, that " amongst all the known combustible bodies charcoal is the only one which does not combine directly with oxymuriatic gass." The remainder of this curious paper is devoted to a farther elucidation of some previous opinions advanced by the author upon the sulphur and phosphorus. In consequence of the extent of the new discoveries, and the still greater extent of the new views which such discoveries have opened in the regions of chemistry, Mr. Davy forcibly adverts to the imperfection of the modern chemical nomenclature. "It is in many cases," observes he, "connected with false ideas; and in a more advanced state of the inquiry, it will be necessary for the progress of scionce, that it should undergo material alterations."

III. Case of a man who died in consequence of the bite of a Rattle snake; with an account of the effects produced by the poison. By Everard Home, Esq. F. R. S. Our readers are well acquainted with the general features of this case through the medium of the newspapers. The man, aged 26, was bitten in the

thumb and fore-finger when in a state of intoxication. The adjoining parts soon swelled and became tense, and the inflammation extended gradually up the whole of the arm, and down the side of the body. The wounds were bathed with aqua ammoniæ puræ, and the internal medicine relied upon was volatile alkali: the patient lived seventeen days after the bite, and appears rather to have fallen a sacrifice to the secondary effect of gangrene than to the direct influence of the poison itself.

IV. "An Analysis of several varieties of British and Foreign Salt, (Muriat of Soda) with a view to explain their fitness for economical purposes. By Wm. Henry, M. D. F. R.S." &c. The intrinsic value of this paper has induced us to copy the greater portion of it into another department of this volume; and it is unnecessary to notice it farther. V. " Description of an extraordinary Human Foetus: in a letter from Mr. Benjamin Gibson, Surgeon, to H.L. Thomas, Esq. F.R.S." This is a very curious instance of monstrosity, consisting of two fœtuses, obviously of different sexes, united into one form, the osseous structure, vascular system, and distinct organs being in some cases double, and in others single, yet in the last instance so accommodated as to answer the double demand of the twin-figure. Though still-born, it is said to have reached "the full period of utero-gestation."

VI." Observations on the Effects of Magnesia, in preventing an increased formation of Uric Acid; with some remarks on the Composition of the Urine. Communicated by Mr. W. T. Brande, F. R.S." &c. The idea of employing a substance that might prevent the formation of uric acid, in preference to one that

2.2

night

might destroy it when formed, was first suggested by Mr. Home. Mr. Hatchett hinted that perhaps magnesia might have the best chance of answering such a purpose, and Mr. Brande upon this double authority has employed it, and in a variety of cases which are here detailed with much apparent success. This paper is well worth attention.

VII.

Supplement to the first and second part (parts) of the paper of experiments, for investigating the cause of coloured Concentric Rings between Optic Glasses,. and other appearances of a similar nature. By William Herschel, LL. D. F.R.S." The points chiefly aimed at in this elaborate article are the following supplemental considerations which prove that there are two primary prismatic bows, a blue one and a red one. Illustration of the dependance of the streaks of both the bows upon the critical separation and of the dependance of the rings seen in a prism in this state. Remarks on colours supposed to be produced by thin plates, or wedges of air. Experiments on the multiplying power of surfaces in contact which modify the form of prismatic appearances. Of the breadth of the streaks compared to that of the bows, and the cause why they must take up broader space than the bows from which they are derived. Of the manner in which rays that are separated by critical reflection or intromission come to the eye.

VIII. "On the Parts of Trees primarily impaired by Age. In a letter from T. A. Knight, Esq. F.R.S. to the Right Hon. Sir Jos. Banks," &c. &c. This is also a very valuable paper, though in some degree conjectural. It is well known that many old stocks will not bear when grafted, and even that some young

stocks become cankered in the same manner. Whence this anomaly? The paper before us goes to prove that the infertility and disease do not in these cases proceed from the stock, but from the graft itself; and that the grafts of all old varieties grow progressively effete, and destitute of power.

IX. "On the Gizzards of Grazing Birds." The muscular stomach, or gizzard of graminiverous and granivorous birds have a near approach to each other, and differs essentially from the membranous stomach of carniverous birds: but grass food requires more powers of digestion than grain food: the paper before us points out in what these additional powers consist, being partly in the position of the muscles of the stomach themselves, and partly in a peculiar swell at the lower end of the esophagus, in which the grass is first deposited, and which has a close analogy with the first and second stomachs of ruminating animals.

X. "Observations on Atmospherical Refraction as it affects Astronomical Observations. In a letter from S. Groombridge, Esq. to the Rev. Nevil Maskelyne, D.D. F R.S." &c. This paper cannot possibly be abridged.

XI." On the Mode of Breeding of the Oviviviparous Shark, and on the æration of the Fatal Blood in different Classes of Animals. By Everard Home, Esq. F. R. S." Skates uniformly produce their young from eggs hatched exterior to the body: in the shark genus, some species produce their young in this manner, and others hatch their eggs within the body. The paper before us examines accurately the mode by which this last phenomenon is accomplished, and the structure of the organs for this purpose. Some

valuable