Miscellaneous Papers. 301 



will absorb them more readily than others. To prove this thesis 

 to our own satisfaction we personally performed his experiment. 



Segregated white blood corpuscles, exhaustively washed and 

 plasma free, were maintained in a salt solution, and at body tem- 

 perature, are indifferent to bacteria, but on the addition of blood 

 plasma they consume their fill of the microbe life. This experi- 

 ment proved one or the other of two things to be true: either there 

 is something in the blood plasma that stimulates the white blood 

 corpuscles or else the plasma must prepare the corpuscles so that 

 they are ready to be absorbed. This suggested to the experimenter 

 that the blood plasma must hold some catalytic agent toward the 

 white blood corpuscle, the nucleus substance, which must prepare 

 the microbe to be absorbed or taken up. We next discovered that 

 a temperature of 65° C. annuls this microbe-destroying capacity. 

 If, however, the microbes were incubated at a temperature ap- 

 proaching blood heat and the temperature then raised to 65° C, the 

 corpuscles would take up the microbes. This indicates the opsonin 

 to be a definite substance because it has a definite point of decom- 

 position. From the observations of others coupled with those of 

 our own we draw the following conclusions about opsonins: 



{a) Opsonin will unite with dead innocuous microbes. 



(b) This union will stimulate the body cells to produce more 

 opsonin, in fact an excess of opsonin. 



(c) The best agent to stimulate this action consists of the dead 

 cells of that microbe which we are seeking to destroy. 



(d) All bacilli stake their existence on the opsonian combat. 

 Doctor Koch in his experiments with tuberculosis along this 



line gave too large doses too close together, with unsatisfactory re- 

 sults. Doctor Wright by giving small doses was able to show that 

 he could treat successfully many localized diseases by inoculating 

 the menstra of the innocuous dead microbe cells. Since then, 

 Doctor Wright and his assistants have been very busy supplying 

 the demand for their opsonin. 



Doctor Wright and his assistants did not understand the chem- 

 istry of the opsonin content and the albumen content of the excre- 

 tions and the lesions of the tubercules. They said, "The lung 

 tissue is filled with a substance which by chemical means exhibits 

 albumen, salts, and nothing else that is characteristic." 



The writer, as a result of his experiments, has reached the fol- 

 lowing conclusions: 



(a) The opsonin content always contained nitrogen compounds 

 of a high albuminous character. 



