DIPHTHERIA BACILLUS. 367 
the same antitoxice serum, but with different diphtheria 
toxins, proved this opinion to be incorrect. Ehrlich’ 
deserves the credit for first clearly perceiving and 
publishing this. He obtained from various sources 
twelve toxins and compared their neutralizing value 
upon antitoxin ; these tests gave most interesting and 
important information. The results in six toxins, 
which are representative of the twelve, are as shown 
in the following table: 
2 |.g | $8d8s8 2832 
| 28 | S2R088 lodged. 
f=] Bn weRoas PES Wo 
a | aR | c8aash leat obs 
a" 24g38 
8 ax Sesset B93 88 oly, aT 
A. | FS. | BREE gD |e e peas) lt icbosiae 
Bq | * o&| S8ouwSs, Boa esa = fatal} Data upon “ toxin 
o'9 Ben | Fo ass |2ous g| doses. specimen given by 
as | OOF) Sep egs (On kS . & Ebrlich 
ne gUa| a Pgks joaggesh rlich. 
aa S72] Syttaa | sagas: 
q@ | Bae) s82e2n asst" ais 
ES | Bem) Fok mrs |e: A888: 
2 0. 03 42 32 10 Preserved.two years. 
4 0. 009 39.4 33.4 6 Old, deteriorated from 
0.003 to 0.009. 
7 0. 0165 76.3 54.4 22 Fresh toxin, preserved 
with tricresol. 
9 0. 039 123 108 15 A number of fresh cul- 
tures grown at 37° C. 
four and eight days. 
10 0. 001 29. 2 27.5 1.7 | Precipitated from 
greatly deteriorated 
‘*toxin.” 
12 0. 0025 100 50 50 Tested immediately 
after its withdrawal. 
From the facts set forth in the tables, Ehrlich has 
derived interesting theories, which, if true, would add 
greatly to our knowledge of toxins, and would also have 
a very direct influence upon the present methods of 
standardizing antitoxin. He believes that the diphtheria 
bacilli in their growth produce a toxin which, so long as 
1 ‘*Die Wertbemessung des Diphtherieheilserums und deren theoretische 
Grundlagen,” Klinisches Jahrbuch, 1897. 
