RESEARCHES ON CERTAIN PROBLEMS OF PLAGUE IMMUNITY 23 



A test was carried out on one day with the serum of a number of 

 horses. It will be seen from the Table XIII. that the only serum which 

 showed marked antitoxic properties was the serum of horse " M," which 

 had been immunised with toxins only. 



TABLE XIII. 



SERUM OF SEVERAL HORSES VARIOUSLY IMMUNISED. 



Test Toxin No. 10 ; tests all carried out on one day. 

 Toxin and Serum mixed and kept i hour at 35° C 



(133) 



