necrosis had set in. The history of the ease, as I afterwards ascertained it, was this: The lady had gone to a dentist to have her teeth filled,—this one among others. The tooth had never ached, but, on cleaning it oat and removing the decayed portions, the dentist said there was a slight exposure of the pulp, and treated it for a day or two. He is a personal friend of mine, and I know him to be a good operator,—honest, careful, conscientious, thorough, and skillful. I cut that tooth carefully in two, in order to see whether the pulp had been devitalized and extracted or not. I found that the pulp had been covered with white oxide of zinc, mixed with oil of cloves, and that over that had been placed a small piece of asbestos, and the cavity filled with oxyphosphate. The cavity had been thoroughly cleaned out, the margins well prepared, and everything about the operation thoroughly done. The abscesses had occurred seven or eight months afterwards. The point I want to bring out in connection with this case is simply this: I had the hardest work in the world to keep that woman from bringing a suit for malpractice against the dentist who had filled the tooth. It was only through the earnest persuasion of myself and another dentist and her physician that she was kept from bringing a suit for malpractice and criminal negligence against a perfectly innocent man.

The other case was one of my own. It was presented at a clinic five or six }^ears ago. One Sunday as I came out of church a gentleman who was waiting for me outside asked me to go down to my office and extract two or three teeth for him. He said he was almost frantic with pain. He was a man of very nervous temperament, and insisted that I should administer gas. He said, "For heaven's sake, don't let me feel any pain." I told him I would give him the gas, and that he would not feel any. I had administered it to him three times previously, with no bad results. There were three teeth that he wanted taken out, two of them with abscesses, and the other one badly broken down. He said, " While I am under the influence of the gas take these two out, and if you get a chance to remove the other one before I become conscious, do so." I placed him under the influence of the gas, which he took nicely; respiration good and pulsation strong. I extracted one tooth; then took out the next one. I said to my brother, " He did not feel it. I guess I will take out the other." There was no movement of a muscle. He wTas perfectly calm and quiet. I waited a little, thinking he was too much under the influence of the gas, and then extracted the tooth. When he came to he said, "Oh, my! that last tooth; I felt every bit of it." I said, "I guess not; you only dreamed it; you never moved a muscle." "I don't care; I felt it. I will tell you what you did. You laid down one pair of forceps, as though you did not like them, and picked up another, didn't you?" "Yes." "You extracted one tooth then?" "Yes." "Then told your brother I did not feel it?" "Yes." "You stood back and ran your fingers through your hair?" "Yes." He said, " I would not have felt that pain for $500. I would have given all I was worth for the power to tell you to stop." The next morning, when he got up, one-half of his head was perfectly gray,—and it remains so. A couple of my professional opponents, generous fellows, went to him and told him they would defray all the expenses of a suit against me for malpractice if he would begin it. That was very kind of them, and I ought to feel very grateful. But he did not bring the suit. He went with me to a physician of well established reputation, who gave the opinion that it was merely a coincidence. But suppose a suit for malpractice had been brought, and I had been taken into court,—see the position in which I would have been placed! Yet I was perfectly innocent. I had done my duty thoroughly and to the best of my ability, and there was nothing in the whole operation that has not taken place ten thousand times. The same thing is done every day in the week, over and over again. The unfortunate result is a thing that is liable to happen, although I never heard of such a case before nor since. What is the explanation of it? One physician says it is due to paralysis of a nerve. The hair continues to grow naturally on that side the same as on the other, except the color. There is no loss of hair. Another physician says it was caused by the excessive pain the patient suffered, and another says it was merely a coincidence, and had nothing whatever to do with the operation I performed.

These cases will serve to illustrate the point I desired to bring out, which is that we are liable to be called into court as defendants in cases of our own, or as witnesses upon some question connected with our profession, and that, therefore, it is our duty to be educating ourselves, so that when the occasion arises we can give honest and valuable expert testimony.

Adjourned. B. C. Nash, D.D.S., Secretary.

0D0NT0L0GI0AL SOCIETY OF PENNSYLVANIA. The regular meeting was held Saturday evening, November 1, 1884, at the office of Dr. M. Lukens Long, No. 720 N. Sixth street, Philadelphia, President G-uilford in the chair.

Henry Leffmann, M.D., D.D.S., professor of chemistry and metallurgy in the Pennsylvania College of Dental Surgery, read a paper entitled

Some Observations On Anesthetics From A Chemical And PhysIological Point Of Yiew.

Anesthesia is the most precious gift of science to man. The elixir of life and the fountain of eternal youth will never be discovered, but the diminution of suffering is fortunately attainable. It has been well said that in the days before the introduction of anesthetics "surgery was agony."

Very few of the now living surgeons can realize other than in imagination the scenes of the operating room fifty years ago, or contrast the spectacle of a patient bound to the operating table? conscious of every movement of the knife or forceps, or of ligations, with the present method, under which the patient tranquilly sleeps, even during the most formidable operations known to surgery.

The number of substances that have been proposed, and more or less used, for the production of general anesthesia is quite large, and, doubtless, if there were a great necessity for a variety of agents,— definite promise of superior advantage in further research,—the number could be vastly increased. Until a very recent period the method of producing anesthesia was by inhalation, but we have now the process of administration by the rectum, and, although perhaps objectionable and even dangerous, yet the results obtained show that the effects of the anesthetic are due to its absorption into the blood, and not to mere influence on the respiratory tract. Leaving out of consideration nitrous oxide and carbonic acid (the latter having been proposed but never regularly used), the general anesthetics consist of volatile liquids, derivatives of the hydro-carbons, particularly of those low in the series. Many of the compounds of this series are unsuitable, either on account of their slowness of action, disagreeable properties, difficulty of preparation, or other incidental causes. The experience of the surgeons of this country has been practically limited to three substances,—ethyl oxide, commonly called ether; trichlormethane, commonly called chloroform; and ethyl bromide. In their physiological action these bodies are all cardiac depressants, chloroform being the most so. The continuation of life requires the maintenance of the functions of the heart, lungs, and central nervous system. Anesthetics attack all three points, depressing the heart power, disturbing the osmodic processes of respiration, and, by poisoning the blood current, affecting the brain. Yet, notwithstanding this, when used cautiously they may be safely employed. Chloroform is undoubtedly the most energetic of the three. Nothing is more regretful in the history of our profession than the deaths from chloroform administered by dentists. Too much stress cannot be laid on the fact that the heart power is so seriously reduced by this anesthetic that it is incapable of supplying the brain properly unless the patient is entirely recumbent. We know, of courser nothing about the intimate action of these agents, and the relative danger is only, therefore, a matter of clinical experience; and upon this topic much difference of opinion prevails. In this city, for instance, are surgeons who rarely use ether, and those who never use chloroform. We may get a suggestion concerning the physiological anesthetics from facts recently derived with regard to intoxicating agents, which are somewhat analogous bodies. It is well known, for instance, that the term alcohol, long restricted to the product of ordinary fermentation, has now acquired a generic meaning, and includes a large number of bodies, some closely resembling common alcohol, and others very different. Without stepping too far into the field of chemistry proper, I may recall to your minds the fact that there are several series of these alcohols, of the first and simplest of which, common alcohol, is the second member. Bach of these series consists of analogous bodies, presenting gradually increasing complexity of structure, but never departing from a certain type. The chemist recognizes in each alcohol an arrangement of atoms into a radicle characteristic of the alcohol and all its derivatives. The radicles and the alcohols which contain them may be arranged so as to show a regular increase of carbon atoms in the order of the natural numbers, one, two, etc. JSTow, the researches of Eichardson, Eabateau, and others have shown, I think, conclusively that the physiological action increases in intensity and danger as the number of carbon atoms increase, so that while wood spirit (methyl alcohol), with but a single atom of carbon, is transient and slight in its effects, those of fusel oil (pentyl alcohol), which has five atoms of carbon, are prolonged and severe. It would be a mere speculation, but still I think not an unreasonable one, to suppose that a part of this difference is due to the lower osmodic power and greater difficulty of oxidation in the pentyl alcohol, these being the two methods by which the system gets rid of injurious matters. Much of the physiological action depends on the presence of particular radicles, as Eabateau claims to have shown and proved by the fact that two such bodies as pentyl formate and methyl valerate, which have the same composition, will produce when administered very different action, because one will produce in the blood the comparatively harmless methyl alcohol, and the other the harmful fusel oil.

Now, it does not seem too violent to apply these facts to our common anesthetics. Nitrous oxide is a substance as near to air in composition as any compound could be. It is highly diffusible, soluble in water, and, as experiment will easily show, capable of acting as a supporter of combustion. The functions of respiration and excretion are, therefore, not much taxed by it. It may subserve slightly the purpose of the air which it replaces in the lungs. Ether is a very different substance; its action is more specific, but it is highly combustible,—as much so as alcohol,—and it is therefore quickly and rapidly oxidized, and the result? of such oxidation is simply carbonic acid products, to which the blood and lungs are accustomed. As the complexity of the hydro-carbon radicles increases the combustibility decreases, and hence the greater difficulty that the blood has in getting rid of the substance. When, however, we introduce into these organic substances elements which are thoroughly foreign to the processes of nutrition, we get more severe results. Modern organic chemistry has given us extended lists of substances perfectly definite in character, analogous to the true organic bodies, but apparently not only incapable of forming a part of healthy tissues, but also inimical to life. We have, for instance, the substitutive compounds of chlorine, bromine, iodine, nitrogendioxide, arsenic, antimony, and mercury. One has only to recall the effect of chloral, iodoform, hydrogen arsenide, and nitroglycerin, and contrast them with the original organic bodies from which they are derived and to which they are related, to see how the new elements added have increased their toxic action. Here it seems to me we have a clew to the marked action of such anesthetics as chloroform, methane dichloride, ethyl bromide, and carbon tetrachloride. Not only are these bodies difficult to break up (chloroform, for instance, will not yield its chlorine even to silver nitrate), but when broken up the halogen must either be set free or converted into an active form of combination. Observations as to the relative danger of anesthetics, of closely allied character, are not entirely reliable, but one of the most recent essays on the subject, treating of the bodies produced by the successive substitution of chlorine for hydrogen, ascribes the most dangerous and prolonged action to the one containing the most chlorine. The series is as follows:

CH3CI. Mono chlormethane.

CH2C12. Dichlormethane or methane dichloride.

CHCI3. Chloroform.

CC14. Carbon tetrachloride.

If the principle here advocated be correct,—namely, that the danger of an anesthetic will be directly as its slowness of oxidation and osmosis, and the presence in it of elements foreign to the typical organic bodies,—we will have indications as to the directions which our researches for new agents should take.

In the actual use of these agents, of course, the physiological notion may be controlled by the manner of administration. I have already referred to the danger of using chloroform in the upright