42 



MODERN BIOLOGIC THERAPEUSIS 



from the results they produce. They have never 

 been isolated and we do not know their chemical 

 nature; but they are inseparable from one or 

 the other of the serum proteins and may have 



Ivon Petrovitch Pavloff (1849-). 



the same chemical characteristics. They are un- 

 stable compounds, being easily destroyed by 

 heat and by various chemical agents. They are 

 demonstrated and their approximate concentra- 

 tion determined by their reactions with the cor- 



