Diphtheria Antitoxin. 



233 



respectively showed by this test that the second contained more 

 antitoxin than the first. 



In this connection it is well to recall that according to the work 

 of Roux, 1 Danysz, 1 Momont 1 and Cruveilhier, 2 the results ob- 

 tained with antitoxic sera by Ehrlich's method do not always 

 parallel those obtained by the French method — a method which 

 has at least the merit that its results are based on animal experi- 

 ments, the conditions of which correspond in a measure to those 

 which obtain in the actual treatment of the disease. These 

 workers claim that in some cases the results are not only not 

 parallel but may even be the reverse of each other. On the other 

 hand according to the work of Marx 3 the two methods give parallel 

 results. No comparison between the test described here and the 

 French method has yet been carried out. 



4. It would be of interest to know whether washed diphtheria 

 organisms do actually take up antitoxin. A carefully controlled 

 experiment to test this was carried out. Organisms which had 

 been washed several times with saline were mixed with a known 

 amount of antitoxin, allowed to stand for 1 hour at room tempera- 

 ture, centrifuged and the supernatant liquid drawn off. A guinea- 

 pig test with an appropriate amount of toxin showed a fall in 

 antitoxic content of the mixture. The difficulty with this experi- 

 ment is that it is not known when the cells are sufficiently washed. 

 It is proposed to repeat this experiment in the following way: 

 Wash diphtheria cells several times and then wash again batches 

 of these cells and test the first and progressively washed lots to 

 see whether a point is reached where the drop in antitoxin reaches 

 a constant. 



Summary. 



Both acid and serum agglutination of Park 8 strain of B. 

 diphtheria are inhibited when the organisms are first sensitized 

 with diphtheria antitoxin; when diphtheria-agglutinating serum 

 is used instead of antitoxin, serum agglutination is inhibited but 

 not acid agglutination. 



This inhibition phenomenon with antitoxin is specific, at least 

 for the Park 8 strain. 



^Abstract in the "Bacteriology of Diphtheria"; Nuttall, Graham, Smith, 1913, 



525. 



2 Cruveilhier, Ann. Inst. Pasteur, xix, 1905, 249. 



3 Marx, Zeit. f. Hygiene, 1901, xxxviii, 372. 



