238 CLINICAL BACTERIOLOGY. 



and Boer conclude the description of this rather complicated 

 procedure with the following statement : If the readily 

 soluble specific toxin has been cleansed as thoroughly as 

 possible and deposited upon the filter, it will be completely 

 absorbed by hardened filters, and there will be nothing to 

 suggest its presence except a little salt, or the yellowish 

 discoloration of the filter, which is often quite considerable, 

 especially in the case of the tetanus-toxin. The activity of 

 these substances will, therefore, not be expressed by the 

 sum of decimals, but to a certain degree only as integers. 

 For quantitative studies of the tetanus-toxin the bouillon- 

 filtrate appears for the present, therefore, to be the best 

 suited. 



Tetanus-infection in Human Beings. The portal of 

 entry for tetanus-bacilli in human beings may be con- 

 stituted by any lesion of the external integument. The 

 tetanus-bacillus has been repeatedly demonstrated in the 

 earth, especially in that which has been manured, and more 

 particularly in the ' uppermost layers; in the dust of the 

 crevices of floors ; in manure from horses and cows. If a 

 certain amount of any of these substances be introduced 

 subcutaneously in guinea-pigs, there result, usually, ma- 

 lignant edema and, rarely, tetanus. This result depends 

 upon the fact that the bacilli of malignant edema, frequently 

 present in earth and in manure, overrun and suppress the 

 tetanus-bacilli. In order to determine whether tetanus- 

 bacilli are present in suspected material (earth, etc.), bouillon 

 mixed cultures may be made, according to the suggestion 

 of Sanfelice, and kept for a considerable length of time in 

 the thermostat, and then filtered through porcelain cylin- 

 ders. The results of injection of the filtrate will decide 

 whether the material examined contains tetanus-bacilli 

 or not. 



Tetanus in human beings is a toxic disease, just as is 

 tetanus in animals. In human beings also the bacilli never 

 enter the blood or the viscera, but remain confined to the 

 site of original infection. On the other hand, the presence 

 of the tetanus-poison in the blood in cases of tetanus has 

 been demonstrated by successful intoxication of mice with 

 the blood-serum from such cases. Likewise, a substance 

 has been obtained from the liver, the spleen, and the spinal 

 cord of a patient dead of tetanus by precipitation with al- 

 cohol, and which, dissolved in water, is capable of destroying 



