82 



At 7.20 p. m. 20 cc. of the filtrate were injected by means of an 

 appropriate syringe with hypodermic needle into the left median 

 cephalic vein of Jose Ojeira with entirely negative results. 



A second portion of the blood serum of Filomena Martinez was 



pipetted off and diluted with an equal quantity of physiological salt 

 solution, and filtered through a small Berkef eld filter, as follows : 



A new Berkef eld filter was prepared by thoroughly washing by 

 allowing water to pass through it for several hours, and then ster- 

 ilized in dry heat. 



