550 Dr. A. Macfadyen. Upon the Properties of an [Mar. 2, 



was tested by intravenous injection in rabbits. The endotoxin likewise 

 killed rabbits acutely, e.g., 1/10 c.c. killed with diarrhoea and collapse, and at 

 times within two hours, whilst 1/20 c.c. was not infrequently a lethal dose. 

 The onset of the toxic symptoms usually occurred in from one to two hours. 

 The conditions were therefore sufficiently stringent in respect of any 

 antitoxic action of the treated goats' serum. I satisfied myself that neither 

 the goats' nor rabbits' serum possessed any appreciable antitoxic power for 

 the toxins employed. Controls were subsequently found to be unnecessary. 

 Three cubic centimetres of normal goat and rabbit serum did not neutralise 

 two or ten lethal doses of the cell juices. The serum of the treated goats 

 was tested against multiple lethal doses of the endotoxin. An estimate was 

 likewise made of the agglutinative and bacteriolytic properties of the 

 serum. I now proceed to an account of the first successful immunising 

 experiment. 



Billy Goat I. — Eeceived following intravenous injections of toxic cell juices 

 of B. typhosus : — 



1905. 









1905. 









May 16 



1/20 



c.c. 



111. 





,. 1 



c.c. 



No symptoms. 



„ 24 .... 



1/10 



» 



111. 



„ 14 .... 



1-5 



)> 



No symptoms. 





.. 1/5 



>> 



111. 



„ 21 .... 



, 1*5 



j; 



No symptoms. 



„ 9 .... 



.. 1/2 



J> 



111. 



„ 28 .... 



2 



J> 



111. 



„ 16 .... 



1 



5> 



111. 





• " 2 



)' 



No symptoms. 



„ 23 .... 



i 



)1 



111. 



„ 11 .... 



2-5 



J5 



Dead next day. 



„ 30 .... 



i 



. 5J 



111. 











It was evident that with succeeding animals an even more careful system 

 of dosage would have to be adopted. The goat was bled at intervals and its 

 serum tested. In all instances the serum-toxin mixture was kept at 37° C. 

 for 30 minutes previous to intravenous injection in the rabbit. The 

 results are given in Table II. 



I. — test of Normal Goat's Serum. 



Rabbit I .. ... 3 c.c. serum +1 c.c. toxin. Dead. 



„ II 2 „ +1-,. „ Dead. 



„ III Control. 1/10 „ „ Dead. 



„ IV „ 1/20 „ „ Diarrhoea.. • 



Three cubic centimetres of normal serum did not neutralise 1 c.c. of a 

 toxic cell juice of which 1/10 killed and 1/20 c.c. produced acute diarrhoea 

 in the rabbit. 



