SCIENCE. 



[N. S. Vol. XVIII. No. 444. 



That anti-lia^morrliagins, like other, anti- 

 toxins, etc., could be produced experiment- 

 ally must be inferred from Ehrlieh's pro- 

 duction of anti-ricin ; for although he failed 

 to distinguish between the hsmorrhagic 

 and agglutinating principles in riein, yet 

 the neutralizing value of his anti-ricin 

 seems to have included all the riein prin- 

 ciples. 



If I have dealt somewhat fully with this 

 topic it is, first, because of its importance 

 to human medicine, and second, because in 

 its light I must regard the outlook for a 

 better understanding of a very obscure, 

 serious and difficult pathological condition 

 in man as of considerable brightness. 

 Moreover, it may not be an Utopian dream, 

 in view of what has already been gained, 

 to look forward to the production of an 

 antidote that, by neutralizing this poison 

 for vascular endothelium, may provide a 

 rational and certain therapeutic agent to 

 combat this form of hfemorrhage. 



I shall ask you to turn to another aspect 

 of my theme, which relates to the occur- 

 rence, under natural conditions, of a whole 

 host of cell-destroying— cellulieidal— sub- 

 stances in blood serum which, up to now, 

 have received almost no attention, and 

 which I regard as not without significance 

 to human pathology. When one considers 

 the diversity of agglutinines and solvents 

 for blood corpuscles, bacteria and other 

 cells contained in normal seriun or open to 

 experimental production, it will cause no 

 great surprise to learn that the serum of 

 warm- and cold-blooded animals contains 

 corresponding active principles for kidney, 

 liver and testicular cells. Dr. Noguchi and 

 I have been engaged, during the past win- 

 ter, in studying these cytotoxins, and have 

 found them to have a wide distribution and 

 to possess a considerable degree of activity. 



In view of the ever-increasing number of 

 activities with which almost daily discovery 



is endowing our body-fluids, the question of 

 the independence and specificity of their 

 constituent active principles has come to be 

 an important one. In the studies under 

 consideration we could show, by means of 

 absorption test, that the agglutinines and 

 solvents for blood, kidney, liver and tes- 

 ticular cells differ among themselves, and 

 the removal of a part of them by means of 

 certain of the cells does not prevent the 

 action of the serum upon the remaining 

 cells; from which it could be concluded 

 that these principles are at least specially 

 adapted to given cells. A general reduc- 

 tion in the activity of the serum which has 

 lost a part of the solvents also suggests 

 that they are not specific in the strictest 

 sense. 



It woiild carry us too far afield to dis- 

 cuss the different ways in which the mani- 

 fold properties of serum may be explained ; 

 whether by supposing it to be a mine of 

 diverse substances as rich as the endless 

 activities which it exhibits, or whether its 

 effects are produced by combinations and 

 permutations among a smaller number of 

 independent bodies. It is sufficient for the 

 moment to have drawn attention to the 

 multiplicity of the energies of serum in a 

 relatively narrow circuit, in order that I 

 may add a word upon what may not be an 

 impossible form of activity, developed 

 under pathological conditions, within the 

 serum. 



In speaking of blood destruction, I em- 

 phasized the absence from serum under 

 normal states of cytolysins directed against 

 its own cells, and took under consideration 

 the pathological conditions under which 

 a destructive property was apparent. 

 Whether similar harmful properties for the 

 organic cells are developed in seriun has 

 not been considered e-specially, but in view 

 of the diverse activities of bacterial and 

 other poisonous agents, they may well be 



