feel at the prospect of the addition they will make to the corps of respectable practitioners in the United States. Nor can we avoid congratulating our country on the signal benefits conferred upon it by the medical school of Philadelphia, in annually educating so large a number of enlightened physicians, who are qualified to occupy the highest grades of reputation and usefulness in the profession. The learning, zeal and exertion of the Professors of Medicine in that institution do the highest honour to the western world. And we hazard nothing in asserting, that no medical seminary in Europe offers better means of instruction than are now to be found in the University of Pennsylvania.

LECTURES ON MEDICAL AND OPERATIVE SURGERY.

We feel great pleasure in announcing to the public an important extension of the system of instruction now presented to students of medicine at Philadelphia, by an annual course of lectures on Medical and Operative Surgery, delivered by PHILIP SYNG PHYSICK, M. D. of that city. This gentleman was long the favourite pupil of the celebrated John Hunter, and passed many years in the possession and diligent use of all the means of improvement which are to be found in the British metropolis. These lectures were commenced in February, 1801, in consequence of a request communicated to Dr. Physick, in an address drawn up for that purpose, and signed by a very large proportion of the students attending the medical lectures in the University of Pennsylvania. They are altogether of a practical nature. The eminent qualifications which Dr. Physick possesses for conducting this department of instruction, particularly his profound skill in anatomy and all the other auxiliary branches of knowledge, as well as his admired expertness as an operator, are so generally known in the United States as to render any encomiums from us entirely superfluous.

FOREIGN.

CHEMICAL AGENCY OF THE TWO ELECTRICITIES,

It may not be known to many of our readers, that, from a consideration of electric phenomena, especially those displayed by the Galvanic apparatus, Dr. Gibbes has been led to doubt the correctness of some important conclusions which form the basis of the chemical theory of Lavoisier.

The terms oxygen and hydrogen are, like some others used by naturalists, names applied to unknown causes of well known effects. If these terms were explained to stand for nothing more than a power existing somewhere of producing well defined effects (as the term Magnetism, e. g.), Dr. Gibbes would not be found to differ from Mr. Lavoisier. He would only suggest to what known agents certain results might be attributed. Oxygen and postitive electricity might be convertible terms; but Mr. Lavoisier assumes the existence of two substances which cannot be exhibited to any of our senses, by way of explaining phenomena which are more simply explicable by reference to agents, the existence of which is demonstrable to our senses, and which are clearly adequate to the production of every effect.

Lavoisier attributes weight to oxygen, and calls it the ponderable basis of oxygen gas. Dr. Gibbes conceives himself warranted, by experiment, to say that oxygen gas is produced by the union of positive electricity with water; hydrogen gas by the union of negative electricity with water; and that water, uniting in different proportions with the two electricities, is the ponderable part of the elastic fluids. It is evident that the wire from the Galvanic pile or trough, which is found to be positively electrified, produces oxygen gas when immersed in water. The negative wire, in similar circumstances, produces hydrogen gas. By the positive electricity metals are oxydated-blue vegetable colours are reddened. The acidifying effect of electric commotions in the atmosphere on weak fermented liquors is well known. By the negative electricity the vegetable blue is restored-the oxydated metal revived.

These circumstances, among others, lead Dr. Gibbes to conclude, that when hydrogen gas is produced by the affusion of water on red-hot metal, and the metal is at the same time oxydated, a decomposition of fire, rather than of water, has taken place: that the hot metal has parted with negative electricity, which, uniting with a small proportion of the water, has formed hydrogen gas: that a greater proportion of water has united with the positive electricity, and entered as oxygen gas into combination with the metal. When the two

gases are inflamed together, the spark attracts to itself, in due proportions, the two electricities contained in the two gases, which unite with explosion, and produce fire. The water with which they were before combined is of course depo sited.

It is well known that each of the electricities repels its

like each attracts its opposite. The two electricities are found to reside in almost all substances; perhaps blended in different proportions in all solids and liquids. It is, however, probable, that in uniform fluids the two electricities are almost or entirely distinct. Inflammable substances burn in oxygen gas, not in hydrogen gas: (at least not in the latter except under very peculiar circumstances. In Accum's Chemistry an experiment is mentioned, in which a mixture of sulphur and copper-filing was inflamed both in hydrogen gas and in carbonic acid gas). But the reason why, generally speaking, combustion may be effected in the former, and not in the latter, is, no doubt, owing to the prevalence of negative electricity in all inflammable substances. Thus, when a red-hot metal is oxydated by affusion of water, the quantity of hydrogen gas is enormously disproportionate to that of the oxygen gas which may be forced from the oxyd. Neither of the gases can be inflamed separately, because fire depends on the union of the two electricities; and such union cannot be effected unless both are present in due proportion.

The separate electricities appear to have some properties which they no longer possess in their united state. They constitute the permanent elasticity of the aeriform fluids, which are incompressible by cold, probably by a more perfect union with water than takes place between fire and water, when expanded as a liquid, or in the form of vapour.

Ishall no farther anticipate Dr. Gibbes's developement of his theory, which he will no doubt illustrate by a due detail of experiments, showing, in regard to the principal phenomena of chemistry, that we have abundant evidence of the agency of the two electricities in the production of results attributed to the operation of the hypothetical oxygen and hydrogen; and that the action of the former is distinguishable in, and affords an easy solution of certain phenomena which the Lavoisierian principles can in no way be applied to explain. [Lond. Month. Mag.

Note.-In Dr. PHYSICK'S Communication, p. 36, after the words, "the ether evaporates, and leaves the gum in its original state," add the follows ing, viz. It must be observed, with respect to the ether, that if it be very pure, it unites with the elastic gum, and softens it very much, on which account I prefer the ether as it is commonly sold in the shops, and which is so weak that it will not unite with the gum, but extracts what remains of the spirit of turpentine very effectually. In this the elastic gum may remain about twelve hours.

MEDICAL REPOSITORY,

FOR

AUGUST, SEPTEMBER AND OCTOBER, 1803.

ARTICLE I.

An ACCOUNT of the EXAMINATION of the BODY of a little Boy who died of the HYDROPHOBIA; intended to show the probable Success of Dr. PHYSICK's Proposal for preventing Death by making an artificial opening into the Windpipe. By BENJAMIN RUSH, M. D. Professor of Medicine in the University of Pennsylvania: in a Letter to Dr. EDWARD MILLER.

DEAR SIR,

N the first number of the fifth volume of your Repository, Dr. Physick has supposed death from Hydrophobia to be the effect of a sudden and spasmodic constriction of the glottis, inducing suffocation, and that it might be prevented by creating an artificial passage for air into the lungs, whereby life might be continued long enough to admit of the disease being cured by other remedies. The following account of a dissection is intended to show the probability of the Doctor's proposal being attended with success.

On the 13th of September, 1802, I was called, with Dr. Physick, to visit, in consultation with Dr. Griffitts, the son of William Todd, Esq. aged five years, who was ill with the disease called Hydrophobia, brought on by the bite of a mad dog, on the 6th of the preceding month. The wound was small, and on his cheek, near his mouth-two circumstances which are said at all times to increase the danger of wounds from rabid animals. From the time he was bitten he used the cold bath daily, and took the infusion, powder and seeds of the Anagallis, in succession, until the 9th of September, when he was seized with a fever which at first resembled the remittent of the season. Bleeding, purging, blisters, and the warm bath were prescribed for him, but without success, VOL. I.

The last named remedy appeared to afford him some relief, which he manifested by paddling and playing in the water. At the time I saw him he was much agitated-had frequent twitchings-laughed often; but with this uncommon excitement in his muscles and nerves, his mind was unusually correct in all its operations.

He discovered no dread of water, except in one instance, when he turned from it with horror. He swallowed occasionally about a spoonful of it at a time, holding the cup in his own hand, as if to prevent too great a quantity being poured at once into his throat. The quick manner of his swallowing, and the intervals between each time of doing so, were such as we sometimes observe in persons in the act of dying of acute diseases. Immediately after swallowing water, he looked pale, and panted for breath. He spoke rapidly, and with much difficulty. This was more remarkably the case when he attempted to pronounce the words carriage, water, and river. After speaking he panted for breath in the same manner that he did after drinking. He coughed and breathed as patients do in the moderate grade of the Cynanche trachealis. The dog that had bitten him, Mr. Todd informed me, ́made a similar noise in attempting to bark a day or two before he was killed. We proposed making an opening into his windpipe. To this his parents readily consented; but while we were preparing for the operation, such a change for the worse took place, that we concluded not to perform it. A cold sweat, with a feeble and quick pulse, came on; and he died suddenly, at 12 o'clock at night, about six hours after I first saw him. He retained his reason, and a playful humour, till the last minute of his life. An instance of the latter appeared in his throwing his handkerchief at his father just before he expired. The parents consented to our united request to examine his body. Dr. Griffitts being obliged to go into the country, and Dr. Physick being indisposed, I undertook this business the next morning; and, in the presence of Dr. John Dorsey, (to whom I gave the dissecting knife) and my pupil Mr. Murduck, I discovered the following appearances. All the muscles of the neck had a livid colour, such as we sometimes observe, after death, in persons who have died of the sore-throat. The muscles employed in deglutition and speech were suffused with blood. The epiglottis was inflamed, and the glottis so thickened and contracted as barely to admit a probe of the common size. The trachea below it was likewise inflamed and thickened, and contained a quantity of mu