178 INFECTION AND IMMUNITY. 



lar sense specific toxins. Some micro-organisms, 

 however, produce more than one toxin. The teta- 

 nus bacillus, for example, secretes, in addition to 

 the toxin causing the nervous symptoms of tetanus, 

 another (tetanolysin, or tetanus hemolysin) which 

 has the power to destroy red blood cells, Ehrlich 

 holds that the diphtheria bacillus produces not 

 only the toxin which causes the acute intoxication 

 of diphtheria, but another of long incubation 

 period which may cause paralysis. Cobra poison 

 has at least two toxins, one which attacks the nerv- 

 ous tissues 1 a neurotoxin and another which at- 

 tacks the erythrocytes ; the two may be separated 

 by appropriate measures. As previously stated, 

 the serum of the eel has a strong neurotoxin and 

 a hematoxin. 



secondary Some micro-organisms produce one or more 

 soluble toxic substances, which it is often difficult 

 or impossible to consider as the actual disease- 

 producing elements of these organisms. Concern- 

 ing a disease which is so well characterized clini- 

 cally as tetanus, it is not difficult to determine 

 by inoculation experiment whether one has in hand 

 the specific toxin. -The proof is naturally much 

 more difficult in infections with streptococci and 

 staphylococci, for example, in which the group of 

 symptoms and the pathologic conditions are not 

 entirely unique for the infection. We are by no 

 means certain that the hemolysin or the leucoci- 

 din (toxin for leucocytes) of the staphylococcus, 

 or the hemolysin of the streptococcus are the para- 

 mount disease-producing toxins of these organisms, 

 although these substances are true toxins. 



