office twice to be dressed. He was then discharged as well.

My three cases were single infection, which is usually the case. Occasionally there will be two-rarely more

than two.

Treatment recommended is varied.

Crocker's first case resisted all forms of treatment, and was on the march for two and a quarter years; sometimes traveling as much as seven inches in the twentyfour hours, and eventually migrated in a pus cavity. It probably died from septicemia.

Hamburger treated his case by excision; Shelmire by electrolysis; Stelwagon recommends cataphoretic application of corrosive sublimate, two grains to the ounce, and to touch the suspected site of the parasite with nitric acid. He doesn't know which was effective. He also suggests a sharp application of high frequency current with the flat vacuum electrode one-eighth inch from the skin to the entire suspected area.

THE RESULTS OF VACCINE THERAPY IN

ACUTE AND CHRONIC INFECTIONS.

BY J. EDGAR PAULLIN, B.A., M.D., ATLANTA.

Of the many infections to which the human body is ever exposed, the organisms most frequently concerned are the streptococcus, staphylococcus, gonococcus, pneumococcus, meningococcus, bacillus diphtheria, bacillus typhosus, bacillus tuberculosis, etc. As a result of the invasion by these organisms we have established in the body a process which may be either acute, chronic, localized or general. In the acute infection the clinical picture varies according to the number and virulence of the infecting organism, being in many cases mild and without systemic disturbances, while in other cases there are the usual symptoms observed in a severe toxemia. Acute infections run a rapid course and end in either recovery or death. Chronic infections, on the other hand, are marked by an insidious onset without, as a rule, violent symptoms, and with a tendency toward very slow or practically no improvement.

Most infections are, however, localized, meaning by this that the invading organism is confined to some one particular area-being careful here to distinguish between the site of the growth of the organism and the product of its activity as illustrated by the absorption of toxins. In fact, it might be said that almost all infections are, in the beginning, localized and only become general on account of an inability of the body to successfully withstand the

invasion of the bacteria so that they enter the blood stream, there multiply and are everywhere distributed throughout the body, producing the condition commonly called septicemia.

The portal of entry of these organisms is at a place far removed from the action of the blood fluids, or in that portion of the body which requires for its maintenance a comparatively small amount of blood or lymph. In other words, the organisms enter and multiply in an area of lowered bacteriotropic pressure.

In combatting the invading organisms the body makes use of the protective substances normally present in the blood fluids-agglutinins, precipitins, lysins, opsonins, etc. Time does not permit a detailed statement concerning the action of each of these substances, yet it is generally believed that the most important role is played in the protection of the body by the opsonin, and the amount of resistance offered to the invading organisms is proportional to the amount of opsonin present in the blood. One can not pass over this phase of immunity without referring to the work of Metchnikoff whose patient and untiring efforts and by numerous experiments attempted to show that the resistance to infection was due to the protection furnished by the polymorphonuclear-leukocytes. While the greater number of the facts observed by Metchnikoff have been shown to be due to other agents than the polymorphonuclear-leukocytes per se, at the same time one looks upon his work with the profoundest respect.

The work of Denys and Leclef (1), Mennes (2) demonstrated that there is a substance in the blood which influences phagocytosis. Leishmann (3) in 1902 published a simple method of estimating the amount of phagocytosis against the staphylococcus aureus in a patient the subject of this infection. It remained, however, for Wright (4) to give experimental proof of the existence of a sub

stance in the blood fluids which so acted on bacteria as to cause them to be ingested by the phagocytes, and to show that the leukocytes when freed from blood serum possessed little or no phagocytic power. He showed that this substance, which so acts on bacteria as to render them capable of being ingested by the leukocytes, is present in the blood of normal individuals, and to it he gave the name of opsonin. About this time Neufeld and Rimpau (5) made independently similar observations in working with antistreptococcus serum. Later Opie and Barker (6) have brought forward the fact that the leukocytes possess certain digestive ferments-leukoprotease-and it is by this means that after the ingestion of these bacteria the enzyme so acts on them as to render them harmless.

Wright has also called attention to the fact that in patients the subjects of chronic infections that the opsonic content of their blood is lower than that of an individual who is normal. For instance, he has shown that in a patient the subject of a chronic infection that the phagocytes of this patient when mixed with the patient's serum are not able to ingest as many bacteria as when the phagocytes are mixed with serum of a normal individual. The question arises naturally then as to whether it is possible to raise the opsonic content of the blood so as to increase the power of the leukocytes to ingest bacteria, and it has been experimentally shown that this is quite possible and takes place when an appropriate vaccine is injected, much after the same manner as it is possible to increase the agglutins. It is entirely possible to increase the opsonic power of the blood so that it will influence many times. more bacteria than the blood of a normal individual.

Vaccines. A vaccine is a sterilized and standardized culture of any organism. The method generally employed in making a vaccine is as follows: cultures are taken from the infected area and the nature of the infecting organ

ism determined. Sub-cultures are then made and a twenty-four hour growth on agar is then suspended in an 0.85 per cent. salt solution. The number of organisms in this solution are next counted by employing the procedure devised by Wright in which the suspension is compared to the blood; equal parts of the suspension and blood are mixed, smears are made and the number of bacteria and red blood cells in several fields are counted. Knowing the number of red cells to the cm. it is easy to calculate the number of bacteria appearing in an equal amount of the bacterial suspension. Having determined the number of bacteria in the suspension the vaccine is next sterilized by heating to 60° Centigrade for one hour. Sufficient carbolic acid is added to make it up to 0.1 per cent. Cultures are then made from this vaccine to be sure that it is sterile. In case it remains sterile the vaccine is now ready for use.

Chart No. I illustrates graphically the sequence of events following upon the subcutaneous injections of a vaccine.

To obtain this chart the writer made use of himself for experimental purposes. The opsonic content of the blood was determined on three consecutive days previous to the injection of the vaccine. And on the eighteenth of April one hundred million of sterilized staphylococci were injected beneath the skin over the deltoid region. Within twenty-four hours after the injection there appeared in the injected region an area of induration about three cm. in diameter, slightly sensitive to touch, but not painful. At the end of forty-eight hours there was an area of hyperemia just at the point of inoculation. After this time the local features gradually subsided. No leukocytosis was produced by the inoculation.

The condition of the blood is very instructive. Immediately following the injection of the vaccine there was a