Last Work. Final Honors 635 



be run at 9,000 revolutions a minute and (he (luitl must be pH 6.5. It 

 cannot be done if the lUiid is 7.1 J->H. 2. He has shown that the virus 

 multiphcs and must tlicretore be a Uvini; thing. This lie has done by taking 

 0.02CC of the filtered virus and putting it into 5cc of his culture fluid. After 

 three days from the first tube he transfers 0.02cc to a second 5cc. After 

 another three days 0.02cc from the second lube is transferred to a third 

 tube of ^cc and so on for se\en transfers, the last of which is infections. 

 This is Pasteur's dilution method and it leaves no doubt that something has 

 grown. He has obtained about forty cases of the chicken sarcoma in this 

 way, but what disturbs him is that only about 50% of his inoculations 

 take, whereas the filtered virus derived directly from the chicken tumor 

 will infect ei'ery tivie. Dr. Gye finds also that when his transfers become 

 contaminated with cocci and other organisms they cease to be virulent. 

 He formerly bcliercd malignant tumors non-parasitic but now he believes 

 very tirmly that they arc all or most of them of parasitic origin. 



Dr. Smith learned that Dr. Gye had " not been able to demon- 

 strate any organism [in vitro} by stains. . . . His tubes," he said, 

 " do not cloud even faintly unless they are contaminated." ^^" 



Dr. Gye examined the Blumenthal rat-tumor slides and said he 

 thought " they were infections of some sort." In Amsterdam, 

 Smith had read in Surgery, Gynecology and Obstetrics ^^' a paper 

 on " The Experimental Production of Metastasizing Carcinoma in 

 the Breast of the Dog and primary Epithelioma in Man by repeated 

 Inoculations of a micrococcus isolated from human breast cancer." 

 They discussed this subject, and Smith left the laboratory to return 

 for a second visit two days later. 



On April 16 he went to the cancer hospital at Kensington to 

 consult another doctor but, not finding him, he spent some time 

 with Dr. Cheatle and Dr. Murray. On April 17 he went to Rhodes 

 Farm, Mill Hill, and " saw Dr. Gye inoculate chickens with the 

 Rous sarcoma virus." Smith's memorandum read: 



He put into some, also, virus treated with chloroform for two hours 

 ■which he says destroys the virus. Before injecting it he put the tube under 

 an air pump and carefully extracted all the chloroform, otherwise the 

 chickens would die. I suggested to him that his 50% of failures with the 

 cultures, must be due to the fact that he has attenuated his virus (by 

 excessive heat or otherwise) and consequently only the weaker chickens 

 are infected. In that case the others should be vaccinated, and resist the 

 fresh virus. Evidently he is aware of this interesting possibility and has 

 not told me all. 



^^' See, Some newer aspects of cancer rese.irch, op. cit., 599; Recent cancer research, 

 0/7. cit., 251-253. 



""Mar. 1925, 343-352. 



