for excision by the knife. In many cases of cancer they will prove invaluable, and will, I believe, exert a direct local curative influence. Injected into morbid growths, they would so quickly destroy them that the action might have to be conducted while the body was under the influence of an anæsthetic.

In being applied direct to the sensitive unbroken skin, I find that their destructive action is less painful than could be expected. I have made with both compounds a superficial eschar on my arm with no more pain than a slight tingling warmth. What is more, when pain is felt, it may be checked quickly by dropping upon the part a drop of chloroform, which decomposes the alcohol, converting it into chloride salt, and an ether-triethylic —which is inert locally. Again, I find that these alcohols dissolve some of the vegetable alkaloids. Thus opium may be dissolved in them, and a solution of opium in caustic alcohol is made directly by mere addition of the narcotic to the caustic spirit. Practical men will see the advantages of combinations of these alcohols with narcotics. The practice opens the way to one of the greatest needs cf medicine-a sure, rapid, and painless caustic.

The caustic alcohols may be used in combination with local anæsthesia from cold. A part rendered quite dead to pain, by freezing with ether spray, could be directly destroyed by the action of caustic alcohol-a practice very important in the treatment of poisoned wounds, such as the wound from the bite of a snake or rabid dog. It is by no means improbable that some cystic tumours may be cured by the simple subcutaneous injection of a little of these fluids after destruction of sensibility by cold.

Potassium and sodium alcohol, added to the volatile hydride of amyl, dissolve in the hydride and produce a caustic solution. When this solution is applied to the skin, the evaporation of the hydride takes place, and a layer of the caustic substance is left behind. This application would prove very useful to the surgeon in many cases of disease.

The action of the ethylates on the blood is extremely rapid and marked. The red corpuscles are brought by it into solution,

and there forms (quickly in some cases) an almost instant crystallisation of blood; the crystals are acicular, and spread out in arborescent filaments. The arborescent appearance is identical with the crystallization of the ethylates themselves, but the smaller radiant crystals are due, I believe, to the crystallization of the crystalloidal matter of the blood-cells. They are singularly like the crystalline forms which have been described, since the time of Dr Richard Mead, as occurring in the blood after infection by the poison of the viper. One other peculiarity in the action of the ethylates on blood is worthy of notice while they seem to attack and dissolve the red corpuscles vigorously, they act with comparative slowness on the white corpuscles, so that we may see a white corpuscle floating uninjured in a sea of red colouring fluid previous to crystallization, and even adhering to the crystalline points after crystallization.

The ethylates possess also powerful antiseptic properties, so that even nervous matter, which of all animal substance is most prone to decomposition, can be long kept in good preservation in the presence of them.

This was my report in the year 1876 on these ethylates, and since then I have used them often in practice with much success. The ethylate of sodium is the most manageable. It is very easily made, and its caustic property can be changed in different specimens, to suit different cases. The solution I use is one of half saturation, and I keep the solution in a bottle having a glass rod descending from the stopper, the end of the rod being somewhat pointed. With this rod I lift the solution from the bottle and apply it from the point of the rod. At one time I used a glass brush for the purpose, but I found the brush objectionable, the small fibres of glass being disposed to break too easily.

The first idea that occurred to me in respect to the application of the ethylates was founded on their action physically. It seemed to me reasonable to suppose that if the ethylate were applied to a moist external growth there would be produced two changes: a caustic action would be set up, and at the same time the alcohol would cause instant coagulation of the fluids of

the part, so that the destruction of structure would be purely local and concentrated. In addition to this there would be the advantage of the antiseptic action, which is so marked. Three forms of disease were, I thought, amongst the best for its use— cutaneous nævus, lupus, and malignant ulcer.

TREATMENT OF NEVUS WITH SODIUM ETHYLATE.

In 1870 I treated with the ethylate a case of nævus on the neck of a child two years old. Not more than six applications of the fluid were made when the nævus was entirely removed, and a sound surface left. The nævus in this instance was so small I did not consider the trial of sufficient value; but soon afterwards my friend, Mr. Gay, was good enough to show me a case of nævus of the scalp in a child under his care at the Graat Northern Hospital. The nævus was of the full size of a half-crown, and extremely prominent. It had been treated on various plans-by tying, by nitric acid, and other methods, -but without success. Mr. Gay having consented to my request that the ethylate should be applied in this case, I sent a specimen of the remedy to the hospital for use there. Instead of this the patient was sent to my house that I might apply the caustic myself. I commenced by covering the nævus lightly with the solution. The application gave very little pain, but soon a dark surface showed that the caustic had taken effect. Three days afterwards a firm hard encrustation had formed where the caustic had been applied, which encrustation I did not then remove. A few days later, the hard crust being loose, I gently raised it away to find the nævus greatly reduced in size. The ethylate was again applied to the surface of the nevus, and the same process was continued until the nævus was entirely removed, and a natural surface was left. The case was under my treatment nine weeks and three days. Some time afterwards the child was brought to me so completely well that it was not easy to discover where the nævus had been.

Dr. Brunton's cases, which he so ably reported at the Medical Society, are similar in kind, and his results are equally good. I referred at the meeting to some other cases in which I had

used the ethylate. These I will notice at length on some future occasion. It is better now for me to give one or two practical hints for those who wish to use the ethylates.

PRACTICAL NOTES.

In making the ethylate of sodium, which is the most manageable, it is best not to make much at a time, Put half a fluid ounce of rectified alcohol (sp. gr. 0·975) into a two-ounce testtube, set the test-tube up in a bath of cold water, and add, in small pieces at a time, some cuttings of pure metallic sodium. A gas, hydrogen, will at once escape. Add the sodium until the gas ceases to escape, then warm the water in the bath to 100° F., and add a little more sodium. When the gas again ceases to escape, stop the putting in of more sodium; or, if crystallization takes place, then stop. Afterwards cool down 50° F., and add half a fluid ounce more of alcohol. This will give a good working solution, which can be made more active by adding sodium, or less active by adding alcohol.

Put the solution in a glass stoppered bottle, and have the bottle always well closed.

Keep the bottle always in a cold place. Once, a bottle of ethylate, left during summer time exposed to the sun in my laboratory, exploded, so that the bottle was broken and the contents spilled.

Always apply the ethylate with a glass rod.

The ethylate solution must not be mixed with other fluids than alcohol. Mixed with chloroform, in quantity, a violent action is set up, and the ethylate is decomposed into chloride of sodium and an ether-triethylic.

The ethylate is not so manageable for subcutaneous injection as for application to the surface by the glass rod. It specially deserves trial in lupus, in malignant ulcer, and in vascular cutaneous growths and excrescences.

The addition of an alcoholic solution of opium lessens the pain of an application.

The Royal Medical and Chirurgical Society. The first paper read was that on a case of Thyrotomy for the Removal of a Membrane completely Obliterating the Larynx, by Dr. FELIX SEMON. The patient had attempted to cnt his throat, and as the wound healed it was found necessary to perform tracheotomy. The voice gradually became diminished, and laryngoscopically a tough dense membrane was found occluding the larynx between the false vocal cords, with evidences of anchylosis of the left arytenoid cartilage. The operation was undertaken to remove this membrane, and was the third case on record in which thyrotomy had been practised for such a purpose. A modification of Trendlenberg's tampon was employed to plug the trachea. The author urged great caution in the administration of chloroform through the tamponcannula, the liability to asphyxia being greater than when inhaled in the ordinary way. In the operation itself he had intended to only partially divide the thyroid cartilage, leaving its upper part uninjured, so as to ensure subsequent apposition of the parts, but he was compelled to fully divide it. He then found that there was a second membrane in the larynx, at the level of the original suicidal wound, that visible with the laryngoscope being probably due to the adhesion of the false vocal chords. He urged, therefore, im similar cases, an examination through the tracheotomy wound, to ascertain the presence of other membranes. The lower and primary membrane was being excised with a pair of curved scissors, when the patient began to cough violently. It was thought that the tampon-cannula did not sufficiently occlude the larynx, and that perhaps blood had entered the bronchi. In reinflating the tampon the cough was replaced by an intense asthmatic paroxysm marked by extreme inspiratory dyspnoea. No obstruction was found in the tube, but on partial evacuation of the tampon-bag the dyspnoea ceased, showing, the author held, that an excess even of equal pressure on the inner walls of the trachea sufficed to produce reflex spasm. The sudden cough was in corroboration of Stoerck's statement that the posterior wall of the larynx, and especially the interarytenoid fold,