Chapter XII 



THIRD EUROPEAN JOURNEY, COORDINATE STUDY OF CANCER 



RESEARCH, INTERNATIONAL CONGRESS OF PLANT SCIENCES OF 



1926, LAST WORK. FINAL HONORS. 



IF SMITH knew at this time of the studies of Otto Warburg 

 of Berlin, Germany, on cell metabolism and cell chemistry, 

 he did not, so far as this author knows, say so. In 1925 he was 

 to become acquainted with Dr. Warburg and, being given reprints, 

 one ^ especially was to capture his interest and prompt him to 

 write in his diary March 12: 



what I thought out respecting oxygen hunger as the cause of cell division 

 in cancer and published in 1920 in my Textbook he and his assistants 

 have verified experimentally by most delicate and ingenious methods. They 

 show clearly as I have always maintained that the cancer cell is chemically 

 different from a normal cell, stores more acid under anaerobic conditions 

 and cannot get rid of it under aerobic conditions. In this respect it is 

 quite unlike normal embryonic tissue. He says the acid is lactic acid. 

 Query: Does the crowngall organism excrete lactic acid and not formic.'* 

 Ask the chemists to do over again flask cultures of various strains of 

 Bacterium tumejaciens for the presence of lactic acid. Query: Can War- 

 burg be wrong in his conclusions and a part of the acid of cancer cells 

 be formic acid} It is important also for us to make a lot of experiments 

 in 1925 on Ricinus and other plants using dilute lactic acid 1: 100, 1: 300, 

 1 : 500, etc. Carry these along with experiments using ammonium lactate, 

 and others using monobasic ammonium phosphate on Ricinus plants out of 

 doors as well as others in the hot house. 



Smith was to find Warburg believing as he did that " cancer 

 cells behave unlike normal cells and contain unlike substance." 

 How Warburg and his associates determined " the respiration of 

 tissues and how the acid content of cancer cells " proved " very 

 interesting." Smith took two pages of notes on the demonstrations 

 made for him. But he reserved judgment on a few points. He 

 thought that small quantities of acids other than lactic acid might 

 be present and serve to stimulate cell division. Warburg had 

 shown that if grape sugar was present, the cancer cells might 



^ Ueber den Stoffwechsel der Carcinomzelle, Die Naturwissenschaften 12(50): 

 1131-1137, 1924. 



578 



