horses. The best treatment of this kind, in my opinion, is the vaccination procedure of Besredka. In this method a very small quantity of horse serum is given subcutaneously or even rectally and time allowed for its absorption. The amount absorbed at any time will be too small to cause serious symptoms and yet enough to produce anti-anaphylaxis. After anti-anaphylaxis has been established, and this occurs quite rapidly, the full dose may be given subcutaneously with some safety. The only objection to this procedure is that time, an hour or two, is lost. The time could be shortened probably, though at some risk. Besredka has obtained good results with the method in guinea-pigs, and it should receive a full clinical trial.
Friedberger and Mita have recently described another method by means of which they were able to protect guinea-pigs against ten times the fatal dose. This result was obtained by a slow intravenous infusion of serum so that only traces enter the circulation at one time. The time of infusion lasted fifty to sixty minutes in their experiments. It will be observed that the same principle used by Besredka, the production of anti-anaphylaxis, is here also utilized.
The treatment for hayfever has already been mentioned.
Importance of Anaphylaxis.—The phenomena of anaphylaxis which have been briefly discussed in the preceding pages are important because they have given us a deeper insight into certain interesting diseases, the so-called idiosyncrasies or predispositions whose causation was formerly inexplicable. The remarkable fact is now established that an organism may be so altered by the injection of an apparently perfectly harmless proteid, that a subsequent injection of the same proteid acts like a violent poison. Predisposition of an individual to any substance means now that this individual is sensitized to this substance. How this sensitization has been accomplished is still undecided in many instances, but the basic conceptions of anaphylaxis will be a safe guide in solving the problem.
It must be emphatically pointed out that the analysis of anaphylactic phenomena would have been impossible without animal experimentation; the chief advances have been made by the functional investigation of these disturbances in laboratory animals and not by tissue examination after death. Thus the autopsies of those early unfortunate cases where death resulted from the administration of a therapeutic serum, yielded no information whatsoever regarding the cause of exitus. The physicians stood before a riddle, the more terrible because its nature was unknown. Animal experimentation has explained this fatal enigma, partially at least, and the physician no longer stands in helpless ignorance before it. He knows the state now, and some methods to prevent or reduce its dangers have been placed at his disposal which promise a fair success.