A year ago in the meeting of the Connecticut Valley Dental Association, I spoke of hydrogen peroxide and suggested that it might be used for bleaching teeth, but there were so many opinions as to how it should be used that no agreement could be arrived at about the manner of its application. It was thought it might be sealed into the cavity of the dead tooth and then slowly allowed to ooze out, but the objection to that method is that oxygen is disengaged so rapidly that it would finally burst the tooth. Then it was suggested that it might be applied by painting on the outside of the tooth two or three times daily, but the question arose, will the hydrogen peroxide go through the enamel? The enamel, according to the latest investigations, has fine openings. It is a finely-organized structure, and is capable of allowing fluids to percolate by endosmosis and exosmosis, but in all probability this circulation would be so sluggish that it would bleach the teeth too slowly to be of practical value. The cause of the discoloration of the teeth is a disputed point. I have tried in vain to inform myself about it from the journals, etc. The necessity of scientific investigations becomes very apparent when we attempt to discuss this subject.

We cannot intelligently proceed to bleach a tooth before we know what has discolored it. That is something for the investigator in histology to settle. I myself am unable to give an exact opinion. I have only the supposition that the tooth is discolored by a hematin-like substance of the red blood-corpuscles under some form. If we knew in what form the hematin existed in the tooth we could give the exact substance to bleach it. The antiseptic properties of hydrogen peroxide are not due to oxygen, but to ozone. About six years ago a gentleman in Berlin prepared ozonized water by allowing air passing over moist phosphorus to bubble through water. small quantity of ozone, which is always generated when phosphorus is in contact with moist air, was dissolved in the water in this way. This ozonized water was antiseptic and excellent for the treatment of wounds.

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Dr. INGERSOLL: I wish to bring to the attention of the profession an ulcerative process beginning at the apex and reaching to the neck of the tooth, arising from another cause than that of salivary calculus. I assume this to be a fact:-that no pulp dies a spontaneous death without causing disease in the peridental membrane. The forms of disease which may follow are various; it may be chronic inflammation of the peridental membrane; it may be tumefaction of the membrane; it may be a permanent induration of the sur

rounding parts; it may be alveolar abscess, or it may be alveolar ulceration. We often hear the profession speak of ulcerated teeth -using the term synonymously with abscess. I think that very

little distinction has ever been made by the profession between these two terms as applied to the formation of pus about the apical portion of the root. I thought that I had arrived at a very satisfactory treatment of abscess, yet I found cases supposed to be abscess and treated as such, in which my treatment failed; and I did not understand why I failed. But on more careful study of my failures, it dawned upon me that these cases presented a form of disease that is not alveolar abscess, but alveolar ulceration-having none of the characteristics of alveolar abscess, except that of a pus discharge, yet differing from pyorrhæa alveolaris. There was no circumscribed pus-cavity; no formation of a tubular canal running out from the pus-cavity to the surface; no thick ichorous pus, but a thin, watery fluid, and no tendency to swell. I therefore said, this is not abscess, but something else. About this time I extracted a tooth, in the treatment of which I had failed, and I found covering one quarter of an inch of the apical end, a hard, firm incrustation, unlike any salivary calculus, of a very dark color, and much harder than any salivary calculus I had ever seen, and in appearance granular. The inquiry that first came into my mind was, how could saliva reach this point to deposit its lime-salts? The gum was firmly adherent to the neck of the tooth, except at a single point where a lip of gum acted like a valve, permitting egress but no ingress of fluids. I judged therefore that the deposit could not be of salivary origin, for saliva could never get there except by injection. Gravity would not take it there, for the extracted tooth had come from the upper jaw. My next pertinent inquiry was, what is its source-what the conditions of its formation, and what is its nature?

Not being accustomed myself to conduct chemical analyses, and not having secured an analysis from any other person, I have not been able to make reliable comparisons of these deposits with salivary calculus as found upon the crowns of teeth. But it is quite certain that we shall not find in it organic matter such as we find in salivary calculus. And we shall not be likely to find any epithelial scales. The chief fact to be observed is that it is not found in connection with alveolar abscess, but always when present, is found in connection with alveolar ulceration, of which diseased condition it is a result, not a cause. These facts I have thought sufficient to determine the fact that it comes from the liquor sanguinis, the watery por

tion of the blood. I therefore pronounced it sanguinary calculus. In the liquor sanguinis of the blood we have all the elements of bodily nutrition in solution, including the nutrient elements of bone. When in case of ulceration this fluid portion of the blood passes out, by exosmosis, from the blood-vessels, to become the fluid part of pus, it carries with it the lime-salts held in solution and contributes the same to the formation of this calculus. We have also in the blood hematin, which yields its coloring matter to the sanguinary deposit. It undoubtedly contains some broken down tissue, and dead bloodcorpuscles.

With this rational analysis of the nature and source of the deposit, I concluded that we have on the roots of teeth a distinct formation of calcareous matter, usually called salivary calculus, which is not salivary calculus, for the simple reason that it is not and cannot be derived from the saliva. You may designate it calculus or lime-deposit or tartar, if you please; but, deriving its name from the normal fluid which is its evident source, I have called it sanguinary calculus, because that is a term seemingly in harmony with the nomenclature of science. The various calculi found in the body are named from the normal fluid from which they are derived. I wish further to state that these two forms of calculus, salivary and sanguinary, are sometimes found in contact with each other just below the margin of the gum, having a distinct line of demarkation between them.

A case was presented at my office in which there was not the slightest amount of salivary calculus, but about the eighth of an inch below the margin of the gum there was a distinct black line of tartar. This indicated sanguinary calculus, which came from ulceration-not the ulceration I have spoken of as originating at the apex of the root, but an ulceration which might have been produced by salivary calculus. But as it had been there for many years the salivary calculus had wholly disappeared-possibly by a dental operation, or possibly by solution-leaving only the sanguinary calculus, which is known by its color and by its extreme hardness.

Dr. PEIRCE: Do you not always find the alveolar process to a greater or less extent broken down where you find this sanguinary calculus?

Dr. INGERSOLL: It has occurred to some, and did occur also to me, that it is possible that the lime-salts might in part be derived from the broken-down tissues of the alveolar walls; but I think I have seen cases sufficient to warrant me in saying this is not the chief source, for it is more in amount than the wasted alveolar margin

could possibly supply. In the case I have stated, while the alveolar margins were thin as note-paper at this point, the incrustation was thicker than ordinary card-board, so the calcareous deposit could not have been derived wholly or in large part from this source.

Dr. PEIRCE: I wish to confirm the statement made by Dr. Ingersoll, that this deposit at the root of the teeth is from the blood and not from the saliva. I have seen it where I am satisfied there had been no possible connection between the deposits at the root and the secretions of the mouth. This being the case, sanguinary calculus would be a very proper term for it. The condition in which the tooth is found may give us some idea of its origin. The tooth in color is abnormally yellow, the tubuli are all consolidated, the pulpchamber, if not entirely obliterated, is well filled with calcific deposit, and all of the blood which originally went to nourish the dentine is diverted with its lime-salts to the cemental membrane of the root, and there makes an amorphous deposit of lime.

Dr. FRIEDRICHS: I would like to ask Dr. Ingersoll how many cases he has seen under the condition that he has described, where the supposition was that the calculus could not be from the saliva.

Dr. INGERSOLL: I saw a great many cases before I ever understood them, but since I arrived at the conclusion just stated, I have seen not more than twenty cases.

Dr. MORGAN: Have you not found this character of calculus in a large number of cases of the so-called Riggs's disease?

Dr. INGERSOLL I call this one of the manifestations of Riggs's disease.

Dr. RAWLS: There are two ways by which inflammation may take place within the sockets which are occupied by the teeth: first, from external causes; second, from internal causes. External causes pass from without between the gum and necks of the teeth. The internal cause must be one which cuts off nutrient circulation, and this condition is based upon either a want of integrity of the tissues, as the result of a local force operating thereon, or a systemic condition rendering possible to the parts a local expression.

The gentleman has named the deposit upon roots of teeth in pyorrhea alveolaris, sanguinary calculus, because of its analogy to such deposits in other parts of the body wherein such deposits take place, except upon surfaces by inflammatory action. In the valves of the heart, in the kidneys and in the liver, we do not find such deposits in the internal structure within the parenchema of the part, but upon surfaces which are normal or inflammatory, and I appre

hend that if the gentleman will inquire into these cases more fully he will find that where he meets with this "sanguinary calculus," so called, there exists an entrance from below or above, as the case may be, for such deposits to be made, and because such deposits happen to be of a different degree of hardness or of different color, is no reason at all why it should be termed sanguinary calculus. For that matter all such deposits might be called sanguinary, since the materials forming them must at one time or other pass through the blood and be a part thereof. In such cases the deposit is simply an impaction of free lime-salts, the result of purely physical action of the tissues and substances involved, and such as you have seen in cases of so-called Riggs's disease, are concomitants, not causes; they follow in the wake of systemic disturbances which have been caused by the action of mercury, salt, or some of these elements or compounds. Tissues under such an influence are readily broken down, pabulum is wept out to build up that which has been broken down because of its want of integrity, and not entirely because of any special local irritant; such tissues are not capable of reorganizing or re-establishing complete nutrient supply between themselves and the tissues to which they were once united. When ulceration (which means separation) takes place, the supply of nutrition will be cut off and never again in these cases be re-established, simply because the source of supply is in contact with a substance which is inorganic, or practically so. It is disorganized organic material.

Before closing my remarks, I wish to call your attention to the fact that we are teaching our patients and students that it is possible to save teeth in these conditions, when there is no possibility of doing so without violating the veriest laws of nature; we are teaching our patients that we can cause healthy tissue to grow and develop over dead substances, without encysting those substances; we are teaching that this tissue will grow over roughened surfaces partly dead, and we expect that living tissue to remain healthy in contact with the dead, when there is no compatibility between the two.

I would like to have this subject thoroughly discussed. I would like some of the older heads, Drs. Watt and Atkinson, Prof. Taft and Morgan, to bring this subject out; I wish to see where they stand; I want to see whether or no they believe there is something in the body which is not material; if they have any cognizance of a force that is called vital, that will influence-will cause cure of these morbid conditions and a return to health when there are no physical signs of any such possibility.