elapsed from the death of the fœtus and other circumstances, we had every reason to suppose that all the soft parts of it were destroyed by putrefaction; but as this unfortunately had not happened, I was obliged to desist. This I did the more wil lingly, as I was convinced if the patient did not die of symptomatic fever, that the putrefactive process would now go on much more rapidly, and that the bones might be taken away as they became detached. The event justified my expectation. The wound was filled with lint, and the patient put to bed. She lost an inconsiderable quantity of blood during the operation.

Five o'clock P. M. She complains of great pain, and has puked several times; but to this she has been liable every day for some time. No pain upon pressing any part of the abdomen except near the wound. A gentle cathartic ordered.

12th. The wound, which looked foul and sloughy, had discharged a little; a poultice was directed to be applied to it, and the cathartic to be repeated, the other not having operated. The fever not very high.

13th. Much better, the cathartic had operated twice. The appearance of the wound very much improved. On wiping it, two pieces of bone were discharged. The tumour considerably decreased in size.

14th. Passed a bad night in consequence of pain.

15th. More nourishing diet and a few drops of diluted sulphuric acid ordered. The discharge so great that the patient thought some fluid which she drank had passed through the wound; it is not very fetid. An opiate ordered at bed time, as she complained of great pain, and want of rest.

15th. This day I removed the trunk of the fœtus entire, the wound was dressed with prest sponge; she was directed to take bark in the day and opium at night.

After this her health rapidly improved, and all the remain. ing bones of the skeleton were ultimately extracted, those be longing to the head excepted; whether there were any or not is uncertain, for none have ever been felt, and the cavity filled

with granulations from the bottom; they may perhaps be inclosed in a cyst, or they may hereafter be felt and extracted. The woman is now as fat and as healthy as she ever was.

From the size of the bones I should judge the fœtus to have been about four months old; but it might have lived seven, and its diminutive size be the consequence of deficient nutrition, as from its unnatural situation it was probably not so well supplied with blood as it would have been in the uterus.

The importance of the discovery announced in the last celebrated Bakerian Lecture of Mr. Davy, of the Royal Institution of London, and the interesting nature of the experiments detailed in that performance, have induced us to gratify our readers by inserting the whole of it. A few copies only can have been received from Europe, and we do not know that it has yet been reprinted in the United States, so that it is very scarce and not easily procured. For this reason the entire Lecture will be more acceptable than any abstract or abridgement we could possibly give. In connection with this we shall further endeavour to insert, under the article of Intelligence, a summary of the contents of the Bakerian Lecture of the preceding year, on other chemical phenomena of galvanic electricity.

EDITORS.

The BAKERIAN LECTURE on some new Phenomena of Chemical Changes produced by Electricity, particularly the Decomposition of the fixed Alkalies, and the Exhibition of the new Substances which constitute their Bases; and on the general Nature of Alkaline Bodies. By HUMPHRY DAVY, Esq. Secretary to the Royal Society.

I. Introduction.

IN the Bakerian Lecture which I had the honour of presenting to the Royal Society last year, I described a number of de

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compositions and chemical changes produced in substances of known composition by electricity; and I ventured to conclude, from the general principles on which the phenomena were capable of being explained, that the new methods of investiga tion promised to lead to a more intimate knowledge than had hitherto been obtained, concerning the true elements of bodies.

This conjecture, then sanctioned only by strong analogies, I am now happy to be able to support by some conclusive facts. In the course of a laborious experimental application of the powers of electro-chemical analysis, to bodies which have appeared simple when examined by common chemical agents, or which at least have never been decomposed, it has been my "good fortune to obtain new and singular results.

Such of the series of experiments as are in a tolerably mature state, and capable of being arranged in a connected order, I shall detail in the following sections; particularly those which demonstrate the decomposition and composition of the fixed alkalies, and the production of the new and extraordinary boIdies which constitute their bases.

In speaking of novel methods of investigation, I shall not fear to be minute. When the common means of chemical research have been employed, I shall mention only results. A historical detail of the progress of the investigation, of all the difficulties that occurred, and of the manner in which they were overcome, and of all the manipulations employed, would far exceed the limits assigned to this lecture. It is proper to state, however, that when general facts are mentioned, they are such only as have been deduced from processes carefully performed, and often repeated.

II. On the Methods used for the Decomposition of the fixed Alkalies.

The researches I had made on the decomposition of acids, and of alkaline and earthly neutral compounds, proved that the powers of electrical decomposition were proportional to the

strength of the opposite electricities in the circuit, and to the conducting power and degree of concentration of the materials employed.

In the first attempts that I made on the decomposition of the fixed alkalies, I acted upon aqueous solutions of potash and soda, saturated at common temperatures, by the highest electrical power I could command, and which was produced by a combination of voltaic batteries, belonging to the Royal Institution, containing twenty-four plates of copper and zinc of twelve inches square, one hundred plates of six inches, and one hundred and fifty of four inches square, charged with solutions of alum and nitrous acid; but in these cases, though there was a high intensity of action, the water of the solutions alone was affected, and hydrogen and oxygen disengaged with the production of much heat and violent effervescence.-The presence of water appearing thus to prevent any decomposition, I used potash in igneous fusion. By means of a stream of oxygen gas from a gasometer applied to the flame of a spirit lamp, which was thrown on a platina spoon containing potash, this alkali was kept for some minutes in a strong red heat, and in a state of perfect fluidity. The spoon was preserved in communication with the positive side of the battery, of the power of one hundred of six inches, highly charged; and the connection from the negative side was made by a platina wire. By this arrangement some brilliant phenomena were produced. The potash appeared a conductor, in a high degree, and as long as the communication was preserved, a most intense light was exhibited at the nega tive wire, and a column of flame, which seemed to be owing to the developement of combustible matter, arose from the point of contact. When the order was changed, so that the platina spoon was made negative, a vivid and constant light appeared at the opposite point. There was no effect of inflammation round it; but aeriform globules, which inflamed in the atmosphere, rose through the potash.

The platina, as might have been expected, was considerably

acted upon; and in the cases when it had been negative in the highest degree.

The alkali was apparently dry in this experiment; and it seemed probable, that the inflammable matter arose from its decomposition. The residual potash was unaltered; it con tained, indeed, a number of dark grey metallic particles, but these proved to be derived from the platina.

. I tried several experiments on the electrization of potash, rendered fluid by heat, with the hopes of being able to collect the combustible matter, but without success; and I only attained my object, by employing electricity, as the common agent for fusion and decomposition, Though potash, perfectly dried by ignition, is a non-conductor, yet it is rendered a conductor by a very slight addition of moisture, which does not perceptibly destroy its aggregation; and in this state it readily fuses and decomposes by strong electrical powers.

A small piece of pure potash, which had been exposed for a few seconds to the atmosphere, so as to give conducting power to the surface, was placed upon an insulated disc of platina, con. nected with the negative side of the battery, of the power of two hundred and fifty of six and four, in a state of intense activity; and a platina wire, communicating with the positive side, was brought in contact with the upper surface of the alkali. The whole apparatus was in the open atmosphere.

Under these circumstances, a vivid action was soon observed to take place. The potash began to fuse at both its points of electrization. There was a violent effervescence at the upper surface at the lower or negative surface, there was no liberation of elastic fluid; but small globules, having a high metallic lustre, and being precisely similar, in visible characters to quicksilver, appeared; some of which burnt with explosion, and bright flame, as soon as they were formed, and others remained, and were merely tarnished, and finally covered by a white film, which formed on their surfaces.

These globules, numerous experiments soon showed to be