praiseworthy reports published by Dr. W. E. Lee and his numerous co-workers.

Dichloramin-T is the abbreviated name of para-toluene-sulfone-dichloramid, CH,C,H,SO,NCI. (The letter T, indicating toluene, distinguishes it from similar compounds which have been or may be made from benzene, xylene, etc.)

titrated with N/10 sodium thiosulfate. solution. Each cc. of the thiosulfate solution is equal to 6 milligrams of dichloramin-T. A strong odor of chlorin and incomplete solubility in chloroform are reliable signs of decomposition of the salt, while extreme turbidity and the formation of crystals in the bottom of the bottle are an indication of the decomposition of its solution in chlor

cosane.

The bactericidal action of dichloramin-T is discussed under the heading of "General action of antiseptics."

It is a yellowish-white crystalline powder, having a sweetish, rather pungent chlorous odor and containing a little over 29 per cent. of available chlorin. It melts at about 80° C. (176° F.). In the solid state, when kept in the dark it is stable. It is practically insoluble in water, but is readily soluble in most organic solvents, i.e. chloroform, benzene, eucalyptol, etc. It quickly reacts, undergoing decomposition with evolution of nascent chlorin when brought into contact with most organic substances, such as acids, alcohol, and the amins, with hydrogen dioxid, water, etc., and certain metals. It should be stored in small amber-colored glass-stoppered bottles and protected from heat.

The strength of dichloramin-T or its solutions may be readily estimated by taking an aliquot quantity, i.e. 0.1 gram of dry dichloramin-T or 0.5 gram of its solution and adding 5 cc. of carbon tetrachlorid and an excess of a 10 per cent. potassium iodid solution and glacial

SOLVENTS FOR DICHLORAMIN-T.

At the early stages of our experimental work we prepared the dichloramin-T solution in accordance with the original suggestion of Dakin, by using such solvents as chlorinated eucalyptol and chlorinated paraffin oil, or a mixture of both. However, it was observed that these solutions produced varying degrees of pain, which we attributed to the irritating effects of the solvents. Chlorinated eucalyptol is an unstable body which readily decomposes in the presence of dichloramin-T by absorbing moisture, resulting in the production of volatile acid substances. Hence, when Dakin announced that he had prepared a new solvent for his antiseptic which eliminated the above disadvantages of the original solvents, we at once tried out the preparation and found it to be fully in accordance with the claims made. for it.

This new compound is known as "chlorcosane." It is a bland, heavy, viscid oil, having a slight yellowish color, and is prepared from hard paraffin melting at about 50° C. (122° F.) by replacing a part of its hydrogen by chlorin. Chlorcosane does not contain any “free” chlorin, although it absorbs from 45 to 55 per cent. of its own weight. The chlorin combines with the carbon of the paraffin somewhat in the same manner as chlorin and sodium combine to form the ordinary inert sodium chlorid. Chlorcosane, by the application of moderate

heat, will readily dissolve from 8 to 10 per cent. of dichloramin-T, which is more than amply sufficient for dental purposes. As the preparation is too cumbersome. to be attempted by the dentist, chlorcosane, as well as dichloramin-T, is best procured through the ordinary trade channels.

PREPARATION OF DICHLORAMIN-T

SOLUTION.

Regarding the concentration of the solution of dichloramin-T for the purpose of treating infected root-canals, we have found that a 5 per cent. solution of the salt in chlorinated paraffin, i.e. chlorcosane, answers our purpose quite satisfactorily. We have heard an opinion expressed to the effect that a 5 per cent. solution is too irritating when used. in root-canal work. We cannot subscribe to such assertions; we rather believe that the pain resulting from its application was due to two causes-a spoiled solution and a faulty technique. Dr. Lee and his co-workers have employed a 5 per cent. solution in many thousands of cases by pouring quantities of a dram or more directly into an open wound without producing the slightest painful sensation. We can fully confirm these facts.

Solutions of dichloramin-T preserve their activity for a limited time only; they usually deteriorate within two or three months, and therefore it is best to prepare a convenient quantity which may be readily used up within a month or so. To prepare an ounce of the solution, 25 grains of dichloramin-T are placed in a dark amber-colored glassstoppered bottle, which must be absolutely clean and free from moisture. One ounce of chlorcosane is added, the whole is thoroughly shaken, and the bottle is placed in a pan containing very hot water or upon a radiator or other source of indirect heat. Within a quarter of an hour complete solution usually results. Direct heat in making the solution is to be avoided, as it is liable to injure the compound. The solution. is immediately ready for use; filter

As stated above,

ing is not necessary. only dark amber-colored or black bottles should be employed as storage vessels; blue glass does not protect the solution against the actinic effects of strong light.

Solutions of dichloramin-T must be carefully protected against heat, light, water, alcohol, and most metals; in fact, most common substances have a strong affinity for chlorin, hence the ready decomposition of this solution when brought in contact therewith. Whenever the solution becomes turbid and forms a deposit of crystals in the bottom of the bottle, or develops a pronounced odor of hypochlorous acid, it should be

discarded. Fresh solutions, if chilled, may temporarily become cloudy, or even precipitate, owing to the separation of either dichloramin-T or of solid paraffin. Slightly warming the solution quickly restores its usefulness.

For office purposes, it is best to keep the dichloramin-T solution in an ambercolored office-preparation bottle with a ground cap. (Fig. 1.) A small glass rod or tube kept in the bottle readily assists in obtaining the few drops necessary for each treatment, to be placed upon an aseptic glass tray. Under no condition should pliers charged with cotton, etc., be introduced into the preparation in the bottle, and no unused portions of the solution must be returned to the stock-bottle.

GENERAL ACTION OF ANTISEPTICS WITH SPECIAL REFERENCE ΤΟ DICHLORAMIN-T.

The terminology of the substances which are used for the purpose of combating infection is frequently employed in a very loose manner, and without regard to its precise meaning. Hence, therefore, it may not be amiss to give as a preamble the definite significance of the more important terms as they are used to designate the specific nature of their action.

It is generally recognized at present that the breaking down of highly organized bodies is brought about by the activity of minute vegetable organisms-the bacteria. This process is known as putrefaction, or, under certain conditions, as fermentation. The presence of certain bacteria and their products is instrumental in the production of severe physiologic changes resulting in the various vital phenomena known as infectious. diseases. The existence of a condition in which bacterial infection and its sequelæ are brought about by the presence of germs or their products is referred to as sepsis, while asepsis implies the entire freedom from such infection. If a primarily septic condition is changed by some method or means which inhibits the growth of the putrefactive organism, antisepsis is induced. Antiseptics, therefore, are chemical agents which merely inhibit the action and growth of bacteria, while germicides destroy the vitality of the infective organisms. Disinfectants also kill the bacteria, and incidentally chemically change their poisonous products to some inert compound. A disinfectant must, therefore, be a germicide, while an antiseptic is not necessarily a germicide nor a disinfectant.

According to Dakin and Dunham, the action of chlorin upon bacteria and their products seems to depend upon a process of chlorination, i.e. the amino acid groups of the proteins readily attack all substances containing "active" chlorin in such a way that the hydrogen attached to the nitrogen atom is replaced by chlorin. The newly formed compounds

The chlorin of these newly linked compounds is still available, and these substances themselves are active germicides. A part of the liberated chlorin is used up by forming inert compounds, that is, chlorin unites with carbon to form inert chlorids. Incidentally, the liberated chlorin is a strong oxidizing (bleaching) agent which is a most beneficial factor in the treatment of pulpless teeth. Chlorin further acts as a prompt deodorizing agent, and possesses the additional remarkable property of digesting and removing sloughing necrotic tissue and of decomposing toxins.

Dichloramin-T shares with other chlorin compounds the property of being a very active lymphagogue, i.e. the amount of wound secretion, especially in the beginning of the treatment, may be considerably increased. The writer's attention has been frequently drawn to this fact by fellow practitioners who have tried the compound in treating root-canals, and who complained of the increased secretion from the canalswhich, incidentally, influences the granulation of the wound most beneficially.

The application of the antiseptic principle as utilized in wound sterilization depends primarily upon three definite conditions:

(1) Absolute contact of the antiseptic with the infecting organism.

(2) Time during which this contact is maintained.

(3) Sufficient concentration of the antiseptic at the points of contact.

Absolute contact between the antiseptic agent and the substances to be acted upon must be rigidly observed, as no antiseptic is known to act at a distance. Consequently all dead tissue (in our particular instance, the débris of the