292 CHEMOTHERAPY 



gested itself to combine the selenium or tellurium with some 

 substance endowed with great powers of diffusion, and to utilize 

 this as a carrier of the cell-destroying metal. As eosin possesses 

 such properties this was selected and a number of eosin-selenium 

 compounds tested out in this direction. While the results obtained 

 were not uniform, a definite cure was nevertheless achieved in 

 several animals, and with the demonstration of this fact the cancer 

 problem seems to have been solved in principle, and it has been 

 proved that not only a growing tumor can be caused to retrogress 

 entirely in consequence of the introduction into the body of a definite 

 chemical compound by the intravenous route, but also that this is 

 possible without causing undue harm to the body at large. 



Of the modus operandi of the selenium we are as yet in ignorance. 

 Neuberg and Caspari have expressed the opinion that the injection 

 of certain compounds of the heavy metals, notably when adminis- 

 tered in colloidal form, favors the self-digestion (autolysis) of the 

 tumor cell, and they succeeded in demonstrating that there are 

 actually substances which possess a selective affinity for cancer cells, 

 and that in cancer mice it is possible to bring about the dissolution 

 of the tumor with such "tumor affinic" substances. They tested 

 out a large number of the heavy metals and could verify Wasser- 

 mann's observation that selenium also possesses such properties. 

 They found, however, that copper and tin are even more active in 

 this respect. These experiments have given rise to most active 

 work along these lines, and sufficient evidence has already accumu- 

 lated to warrant the hope that ere long a method may be devised 

 which may be applicable in the human being also. Some work in 

 this direction is indeed already in progress, but it would be pre- 

 mature to draw any inferences from the little that has as yet been 

 done. 



In conclusion we would yet briefly refer to the work of R. Werner 

 and his collaborators. Starting from a certain parallelism which 

 exists between the effect of radium and .T-ray applications, and the 

 action of certain cholin salts upon the leukocytes and the repro- 

 ductive glands, and the fact, moreover, that there is some evidence 

 to show that the lecithin of the cells is decomposed by the a--ray 

 and radium emanations, with the liberation of cholin, these inves- 

 tigators expressed the opinion that the beneficial effects of radium 

 and a>ray treatment upon malignant growths also might very well 



