26 Kansas Academy of Science. 



with virulent anthrax germs. He had protected twenty-five with at- 

 tenuated anthrax bacteria, but had left the others unprotected. It was 

 a case of Elijah and the priests of Baal, for here he was to demonstrate 

 to many disbelieving scientists and others his claims regarding a matter 

 of truth and falsity. The figure could be carried further. On the 

 second day following a great crowd was present. Twenty-two of the 

 unprotected animals were dead, two were dying, one was sickening. 

 All of the twenty-five protected ones were in good health. This one 

 practice, demonstrated here, has saved France many millions of dollars 

 annually. But what is more important, it laid the foundation for an 

 immense amount of investigation of the whole question of immunization 

 against disease. 



Probably next to that of Pasteur, Paul Ehrlich has done more to ex- 

 plain the mechanism of immunity than any other man. In the later 

 years of the last century (1897) he advanced what is known as "Ehrlich's 

 Receptor Theory." This asserts that cells are able to utilize the food 

 substances present in the blood by means of certain attributes similar 

 to the "side chains" of the "benzine ring." When for any reason these 

 side chains, or cell-receptors, are destroyed, but the cell not killed, there 

 is an overproduction of receptors, and these, cast off into the blood, 

 are the antitoxins and other antibodies often found in the animal body. 



Whether true or not this idea has been very fruitful in explaining 

 many cases of immunity, and in suggesting proper lines of procedure for 

 further attempts at immunization. Of these more later. 



Metchnikoff advanced the so-called "phagocyte theory," and to Wright 

 is due the greater credit for the application of this theory in his work 

 on the "opsonic index." This theory often explains the presence or ab- 

 sence of immunity, and its loss or acquirement, as for instance in 

 tuberculosis. It throws light on the question of the crises that occur in 

 diseases, and often is a guide to the physician in his treatment of va- 

 rious ailments. 



The discovery of the precipitins formed by bacterial action has given 

 man a fine instrument to assist him in determining relationships be- 

 tween animals, and also enables the law to pronounce accurate judg- 

 ment upon the testimony of persons concerning the source of blood 

 stains and meat products. These and other matters of technique are 

 modern parallels of Solomon's wisdom in using the bees in distinguishing 

 between the real and the artificial flowers. 



Through the principle of complement fixation it is now possible to 

 determine with considerable certainty whether one is or has been the 

 carrier of Trepone77ia pallidum, the cause of syphilis, and through the 

 agglutinins it can be determined whether one is or has been recently 

 affected by B. typhosus — the "Widall reaction." Of course this is not all 

 of the ways in which these specific discoveries can be and are applied, 

 but are simply illustrations. 



The peculiar phenomenon known as "Anaphylaxis," or protein sensi- 

 tization furnishes an explanation of the effect of typhoid bacteria upon 

 the body, and of immunization acquired by typho-bacterin treatment. 

 It also explains immunization by vaccination as in smallpox. The body 



