236 THE PROTEAL TREATMENT OF CANCER 



are of so specific a character that they can affect only the par- 

 ticular protein that has invoked them. 



Have they such specificity? 



This, obviously, is an important question. But I think there 

 can be no doubt about the answer. The enzymes that begin the 

 decompounding of the protein molecule are of a tryptic character, 

 closely comparable apparently whether secreted by the digestive 

 glands or by the white corpuscles, and their action is very general. 

 The same enzyme can affect the decompounding of animal and 

 vegetable proteins of the most varied character, as the normal 

 digestion of an ordinary meal in the intestinal tract sufficiently 

 demonstrates. Moreover, it is specifically observed that the white 

 blood corpuscles can attack and destroy bacterial proteins of 

 many types. There are abundant reasons to believe, then, that the 

 enzymes developed as antibodies to any one of the wide range of 

 foreign proteins introduced parenterally may be able to effect the 

 decompounding of other proteins than the particular one intro- 

 duced. 



If, now, we reflect that the cells of a malignant neoplasm are 

 made up of protein which, notwithstanding its close general simi- 

 larity to that of normal tissues, is in a sense a foreign protein; 

 and, moreover, that these cells because of their newness and rapid 

 growth lack something of the stability of matured normal cells, 

 it is readily explicable that they may be attacked by the protein 

 antibodies in the blood and decompounded. 



As suggesting a chemical basis for the expectation that an agent 

 might be developed that would differentiate between normal cells 

 and cancer cells, we may note the researches tending to show 

 that cancer cells have a mineral content in excess of the normal; 

 and, specifically, that the more malignant types of cancer cells 

 are relatively rich in potassium, less malignant ones showing a 

 relative preponderance of calcium ; also the fact, to be dealt with 

 in another connection, that cancer tissue is reported as showing 

 only 70 per cent, of the nitrogen content of normal tissue. 



If the protein antibodies in the blood come in sufficient quanti- 

 ties, it is even conceivable that the cells of the neoplasm may be 

 altogether dissociated, and the neoplasm itself thus eliminated. 

 But of course so radical a result as this could be expected only 

 in very exceptional cases in which the balance between the normal 

 activities of the corpuscles and the activities of the cells of the 

 neoplasm had not been too profoundly disturbed. 



This is perhaps equivalent to saying that success might be 

 expected somewhat in proportion to the stage of advancement of 

 the cancerous condition in general and of the neoplasm in 

 particular. 



A highly important complication is found, however, in the fact 



