Chapter XI 



INVESTIGATIONS CONCERNING THE 

 NATURE OF CYTOST 



It has been pointed out in previous discussion that 

 extracts of autolyzed tissue, if boiled for some time, 

 maintain unimpaired their toxicity for animals. This 

 indicates that the substance in such extracts which is 

 responsible for the various effects described in pre- 

 ceding chapters is quite stable. Furthermore, if solu- 

 tions of cytost are made either alkaline or acid and 

 then boiled, the toxic substance is unaffected. Conse- 

 quently its molecule cannot be readily hydrolyzable, 

 as is that of a simple peptide. 



Sterile solutions of cytost have been kept in sealed 

 ampules for years without any apparent loss in ac- 

 tivity, and dry samples of tissues and tissue extracts 

 likewise maintain their toxic nature. 



Recently confirmatory evidence of the extraordi- 

 nary stability of cytost has come from a quite unex- 

 pected source. The noted archeologist, Flinders 

 Petrie (1932), in his book Seventy Years in Arche- 

 ology, records that contact with the mummy dust 

 caused the onset of various respiratory disturbances, 

 headaches, and colds. Two statements of Petrie are 

 illuminating (page 32) : "All work in the pyramid 



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