IMMUNITY. 355 



and above all the effect upon severe cases must 

 be decisive, a feature in which up to the pres- 

 ent this therapy has failed. 



The collected statistics of the investigation 

 in Germany during the period from October 

 i, 1894, to April i, 1895, showed among 4,450 

 ca^es not treated with serum a mortality of 622 

 or i4.7/ , among 5,790 cases treated with serum 

 a mortality of 552 or 9.5 / . Direct comparison 

 under exactly similar conditions of a sufficient 

 number of cases can however not be made. I 

 do not deny that the curative serum is perhaps 

 able to influence diphtheria favorably, and that 

 hence some slight progress has been made. I 

 deny only that we have the right to set forth 

 such trivial results as " specific," and such a 

 method of treatment as the true and only really 

 causal mode of therapy. On account of the 

 merely moderate success so far attained, we 

 are at liberty to hope that not only so much 

 as is claimed, but perhaps even more, may 

 eventually be compassed in a more simple and 

 reasonable way. 



The hope that immunization as well as cure 

 may be effected with the use of the curative 

 serum, must be abandoned as I have previously 

 shown on p. 341. The slight protection which 

 the body seems to gain from the serum injec- 

 tion is not specific, and, in contrast to a true 



