of which they are the terminations; but they are easily brought together by a slight pressure, such as that exerted by causing the canula to glide along the central stem up to them. When they (the two curettes) are thus brought together to fit one to the other, they thus united form a small smooth steel knob or rounded extremity, about one third of the usual size of the china knob of a Nélaton probe.

There is no difficulty in the manipulation of the instrument. It is a most useful extractor for deciding doubtful cases of lodgment of foreign bodies; it responds as an indicator with even more distinctness than the Nélaton probe in all cases in which that tool would be of service, while it answers for a variety of other cases in which the Nélaton probe would give no indication at all.

Electricity as a means of diagnosis.-One of the most recent inventions by Mr. De Wilde, a civil engineer-consists of an apparatus very compactly arranged in a box of small dimensions. The electric action is excited in a suitable cell; the electricity there developed is increased in intensity by the intervention of a multiplying coil; an exploring probe is connected by insulated wires with the apparatus, and the indications, when the circuit is completed by contact of the two points of the probe with a leaden ball or piece of iron, are given by the striking of a hammer against an alarum bell; the bell sounds at each interruption and renewal of contact of the points with the metal. The exploring probe consists of a long slender tube of smooth vulcanite, containing two insulated needles, the points of which can be drawn within the tube or be made to protrude at the pleasure of the operator.

Messrs. Krohne and Seseman, of London, have also contrived an instrument. The indications of contact with a lodged bullet or other metal are afforded by the means of a galvanometer and of a fine needle working upon a dial-plate, in the same manner as is seen in the ordinary single-needle telegraph.

Longmore alludes to a rough but sufficiently effective instrument, which has been made in the following way:-The magnet of an ordinary pocket-compass, which has had some turns of wire covered with thread wound round it, as an induction coil, is employed for the electric indicator, whilst a piece of copper sheeting, bent round a small plate of zinc, but separated from it by flannel padding saturated with the usual diluted acid, forms the voltaic pile. The exploring instrument is formed by two insulated wires, bound together, but with the points left free; these parts being connected when the circuit is completed by contact with metal, the indication is given by movement of the magnet of the compass.

THE ENDOSCOPE has been suggested. Dr. Fenger, of Copenhagen, in 1869, made experiments respecting its use in gun wounds. During the war he examined several wounds some weeks after infliction, and could see their interior without causing pain. It is not likely to be turned to much practical account. It is obvious that many of the above instruments are not suited for use in the field; the electric explorer is easily disarranged, and various circumstances render such instruments inapplicable. Besides we must recollect

that there must be a limit to search, and this limit must depend on the circumstances of each particular case, and must be decided by the judgment and tact of the responsible surgeon. Moreover the foreign body may become encysted and remain lodged without causing either pain or mischief for many years afterwards.

VIII.-On Vertebrated Probes, Canulas, and Catheters.

Early in 1870 Dr. Squire, of New York, introduced to the notice of the profession a flexible metallic catheter for prostatic retention, the flexibility to be obtained by means of a series of perfect articulations in the vesical extremity of the instrument. A brief account of this instrument, with a woodcut, appeared in the 'Philadelphia Medical and Surgical Reporter' for November 5th, 1870. This catheter was exhibited and its mechanism explained at the New York State Medical Society in February, 1871, and cases detailed in which it had been used with much satisfaction. An account of this catheter, together with a report of seventeen cases, appeared in the American Journal of Medical Sciences' for October,

1871.

Immediately after the exhibition of this catheter at the Medical Society, New York, in February, 1871, Dr. Louis A. Layre exhibited a "jointed silver probe" for exploring tortuous sinuses in cases of diseased bone, &c. The mechanism of this probe was virtually the same as that of Squire's catheter. Dr. Layre published an account of this probe and the vertebrated catheters in the British Medical Journal' for July 22nd, 1871, with a woodcut, but without any acknowledgment of the source from which he derived the idea.

Mr. Durham, in 'Holmes's System of Surgery,' 2nd Edition, vol. ii, p. 511, has invented a tube for use in the operation of tracheotomy, and which he calls the canula with lobster-tail joint; it consists in the distal portion of the tube or canula being composed of several small pieces jointed together in the lobster-tail fashion; a woodcut accompanies the description.

REPORT ON TOXICOLOGY, FORENSIC MEDICINE, AND HYGIENE.

By BENJAMIN W. RICHARDSON, M.D., F.R.S.

Oil of Turpentine as an Antidote against Poisoning by Phosphorus. -Dr. Köhler, of Halle, furnishes this quarter a most able essay on the above-named subject. Regarding the antidotal effects of the oil of turpentine in actue poisoning by phosphorus, there are, he affirms, six leading questions to be answered:

Whether oil of turpentine really is an antidote against phosphorus ?

Whether every kind of the oil of turpentine is equally useful as an antidote against phosphorus ?

Whether the oil of turpentine exercises its antidotal power, when applied to any part of the body whatsoever; or, if this be not the case, which is the fit place and mode of application?

What length of time may be permitted to elapse between the ingestion of the phosphorus and the administration of the turpentine, if life is to be saved?

In what dose and form should oil of turpentine be employed as an antidote against phosphorus ?

What are the chemico-physiological processes whereon the antidotal effects of the oil of turpentine against phosphorus are founded?

1. The first question is answered in the affirmative. "Common commercial oxygenized turpentine is a remedy against phosphorus." 2. As to the second question, whether every kind of oil of turpentine may be used as an antidote against phosphorus, the author says the desired end can only be attained by the common commercial oil of turpentine containing oxygen.

The English oil of turpentine turns the plane of polarization toward the right, while the German, French, and Venetian diverts the plane to the left. The author of the present paper raised the question which of the different kinds of oil of turpentine, the one turning polarization to the right, or those turning it to the left, would form, in connection with phosphorus, the terebinthinophosphorous acid; for it is on this chemical change, this production of a non-poisonous compound, that the antidotal power of oil of turpentine rests. Not having studied this matter before, he made twenty-nine comparative experiments respecting it with a great many different kinds of turpentine. Weighed amounts of phosphorus, together with weighed quantities of oil of turpentine, were heated in previously weighed small glass cucurbits for exactly fifteen minutes in a water bath of 30° to 40° C. (86° to 104° Fahr.), and allowed to get cold in the same place. Waiting just twenty-four hours, he weighed the crystallized substance on filters which had been previously weighed, squeezed these out strongly, and weighed again; extracted the filters and cucurbits with alcohol, dried the whole in the exsiccator as far as possible, and re-weighed. He thus got the per centage

(a) Of the quantity of the terebinthino-phosphorous acid crystallized after twenty-four hours, and produced by the contact of the phosphorus with the oil of turpentine, during a quarter of an hour:

(b) And of the quantity of the phosphorus remaining undissolved, unaltered, crystallized, and adhering to the cucurbit and filter.

The greater the quantity of the resulting crystals of terebinthinophosphorous acid, and the smaller the quantity of the undissolved phosphorus, the more useful as an antidote against phosphorus is the

species of oil of turpentine employed in the experiment to be regarded.

In the case of poisoning with phosphorus, a distinct order should be made on the prescription for the apothecary to dispense long-kept rectified oil.

It is to be remarked that, in the case of all oils that contain a large quantity of oxygen, if there be a surplus of them in proportion to the phosphorus, the product of terebinthino-phosphorous acid will after a time be unexpectedly small. The reason of this is the fact that the harmless product of the combination of phosphorus and oil of turpentine is soluble in the latter substance; the product being formed, indeed, though not crystallized, more of the oxygen is attracted and bound, and finally, agreeably to the description of Bamberger, a red-yellow resinous substance, containing, not phosphorous acid, but phosphoric acid, is separated. Now, since absorption as well as elimination of this said compound, which possesses little or no toxic effects, can but be promoted by its being in a soluble state, a surplus of the oil of turpentine, if the dose be not a poisonous one, may appear to be not only not injurious, but even desirable.

3. To answer the third question, whether oil of turpentine is effective as an antidote against phosphorus in whatever way it may be administered, or to whatever part of the body it may be applied, some ten experiments made on frogs and rabbits have solved the question.

Into these animals the author introduced

(a) Phosphorus into the stomach, and oil of turpentine under the skin;

(b) Phosphorus into the rectum, and oil of turpentine under the skin;

(c) Phosphorus, and afterwards oil of turpentine, into the receptacle of lymph on the back of frogs.

All the animals died, and their bodies showed the characteristic pathological signs of poisoning by phosphorus.

The author's experiments show, with convincing certainty, that it is only by phosphorus coming into contact with oil of turpentine in the stomach that the innocuous combination terebinthinophosphorous acid is produced, and that only then and in that way may oil of turpentine be termed an antidote against phosphorus.

4. The fourth question, how much time may elapse between the ingestion of the phosphorus and the use of the oil of turpentine, without the latter failing to exhibit its antidotal faculty, is by no means in a condition to be answered, too little clinical material being at hand, and animal tests not as yet being, nor to be expected to be, very relevant in this direction. The longest intervals at time between the poisoning and the successful application of the antidotes amounted to eleven hours. (Observation of author in the 'Klin. Wochenschrift,' 1870, No. 1.) However, the conclusion à priori is probably justified, that if a few hours have elapsed since the

ingestion of the phosphorus, and if fat victuals, moreover, have been eaten, and the stomach filled with them, sufficient time has been given for the absorption of the phosphorus, and the possibility of the oil of turpentine being still of use cannot be entertained. Here, however, so many individual differences, species, age, state of nutrition, disposition of the stomach, &c., will have influence, as to forbid the laying down of rules capable of general application.

5. Far easier on the whole is the answer to the fifth question, as to the doses and form in which the oil of turpentine should be given as an antidote against phosphorus. The comparative tests show that all the phosphorus is changed into terebinthino-phosphorous acid, if to 0.01 grm. (15 grs.) of phosphorus, 10 grm. (15.5 grs.) of oil of turpentine, particularly the rectified commercial oil, be added. In other words, a hundred parts of oil of turpentine to one part of phosphorus. But for fresh or recently rectified oil, this assertion requires correction. For oil not rectified, or which has been rectified a long time, fifty parts are sufficient. In cases of poisoning, however, by phosphorus paste, which is very rich in phosphorus, it would be advisable to exceed the dose of 10 grms. (155 grs.) of oil of turpentine, which even large rabbits bear without their constitution in general being essentially disturbed, and even it might be to raise the dose of the antidote to one approaching a toxical height. As to the form in which it should be administered, gelatine capsules containing 5 grm. (7.75 grs.), seem to be preferable to all others. An emulsion is absolutely to be rejected, on account of the accompanying fat or oil, which would assist the absorption of the phosphorus (Mialhe).

6. Lastly, the solution of the sixth question, on what chemicophysiological processes are the antidotal effects of the oil of turpentine against phosphorus founded, has been sought, not by Jonas, as Bamberger incorrectly supposes, but by Peronne, and by the proof of experiments firstly made by the author.

Observing the smell of the urine of two dogs, fed with phosphorus and oil of turpentine, to be like the smell of opodeldoc or camphor, and this odour to get stronger still if the urine had been distilled, the author (not Jonas, as Bamberger states) first arrived at the right explanation of this question. Oil of turpentine with muriatic acid producing the well-known turpentine-camphor, he concluded that probably the phosphorous and phosphoric acids, generated by the higher degrees of oxidation of phosphorus, would produce with the oil of turpentine an analogically constructed species of camphor; and that the urine of the test-animals (camphor itself being excreted through the kidney) derived its specific smell from the turpentinecamphor, resulting from the derivatives of the phosphorus. Furthermore, if the production of such camphor from the contact of phosphorus and oil of turpentine be presupposed, and if this camphor could be proved not to participate in the poisonous effects of the phosphorus, but to have the same effects on the organism as all other kinds of camphor, then it would at the same time be shown how the oil of turpentine operates as an antidote against