Experimental Investigation into the Pathology of Cancer. 393* 



carcinoma of the mamma 1 inch in length, which was placed on agar 

 immediately after the excision of the tumour on May 12th, 1887. It 

 was incubated at 100 F. for some days and has since been kept in a 

 warm cupboard. It does not even now show any naked-eye change 

 and looks as though it had just been removed. 



By the same method we showed the absence of micro-organisms in 

 healthy living tissues. 



Notwithstanding such negative results, we do not by any means 

 think that the evidence from analogy that cancer is probably micro- 

 parasitic in origin is hereby overthrown. For of the micro-organisms 

 already known, some are very selective in regard to artificial culture 

 media, others whose existence admits of easy microscopic demonstra- 

 tion have as yet withstood the efforts made to cultivate them without 

 the body. Moreover, it may be allowable with respect to the parasite 

 itself to conjecture that possibly it does not belong to the Proto- 

 phyta, but to the Protozoa ; in which case the difficulty of artificial 

 culture would be easily explained ; and the enormous rapidity of cell 

 growth in cancer might be thought of as being induced by a can- 

 cerous rejuvenescence setting in in consequence of the conjugation 

 of the " parasite " with the cells of the normal tissues. 



And so the culture medium in the case of cancer, it may be, has 

 yet to be found. 



Human blood serum apparently offers the most likely chance of 

 success, and with it we have made some experiments. We have 

 obtained human blood serum from fresh placentae by the method of 

 expression, and have employed it, both liquid and inspissated, at 

 blood heat. After some experience we found it best to have the 

 blood collected in sterile bottles directly from the divided cord whilst 

 the placenta was as yet nnexpelled. However, no growth has 

 occurred under sterile conditions either when the serum has been 

 simply inoculated or when a piece of living cancer has been placed in 

 or upon it. The tubes were kept in the incubator for some weeks. 

 The same result has also attended the use as a nutrient soil of fluid 

 or inspissated human hydrocele fluid ; e.g., a piece of scirrhus WJIK 

 incubated for eight days on inspissated hydrocele fluid, after which 

 it was kept at the temperature of an ordinary living-room. It has 

 remained sterile and without appreciable change to the present date, 

 twenty months since the experiment was performed. 



Abstract of Three of the Experiments with Human Placental Serum. 



Experiment 1. Sdrrhus of the Breast. Pieces of the tumour were 

 cut with knives which had been wrapped in cotton wool and heated 

 on a previous day in the " iron box " for an hour in the hot-air 

 steriliser at 150 C. The pieces thus cut were put into two tubes of 



VOL. XLVIII. 2 E 



