254 Chapter IX 



act only upon certain special sugars in a manner equally specific. 

 From a logical point of view it might be permissible to attribute 

 the specificity of fixatives to something borrowed from the species 

 of micro-organism that has played a part in their production. It 

 has long been recognised that in old cultures of the cholera vibrio 

 these micro-organisms are transformed into spherical granules, the 

 arthrospores of Hueppe, which closely resemble the granules produced 

 in Pfeifier's phenomenon. There are, then, undoubtedly, vibrioiiic 

 products which act much as do the microcytases, and it would be very 

 interesting if we could find them in the bactericidal ferments of the 

 animal body. An attempt of this kind was undertaken by Emmerich 

 and Low^ who attribute the acquired immunity to a particular sub- 

 stance which they term "Nuclease-Immunproteidin." According to 

 their hypothesis the microbial products which are produced in the 

 animal during the period of vaccination — the nucleases— combine with 

 proteid substances of the blood and organs to furnish the substance 

 to which these authors have given such an elaborate name. In their 

 most recent publication Emmerich and Low even describe a method 

 of producing this substance outside the animal body, by the action 

 of ox blood, or better still pounded spleen, on the nuclease produced 

 by the bacteria found in old cultures. To it they attribute the pro- 

 perty of dissolving the various bacteria, of conferring immunity 

 against and even of curing several infective diseases. But these 

 authors do not say whether this remarkable substance is identical 

 with, or analogous to, the antimicrobial ferments composed, as we 

 have seen, of microcytase and fixative. It must be concluded that 

 they look upon it as being similar to the alexine of Bu^hneiV- which 

 is nothing more than a mixture of the two substances just named. 

 Unfortunately the whole account given by Emmerich and Low will 

 do anything but gain over the reader, and in their publications no 

 proof of their assertions can be found. Several of the facts advanced 

 by them do not fall in with well-established data. Thus they speak 

 [268] of the complete lysis of the bacilli of swine erysipelas by their 

 soluble " Erysipelase-Immunproteidin " in vaccinated animals, a pro- 

 cess that has never been demonstrated by them and which in no 

 way accords with conscientious and carefully carried out observations. 

 On the other hand, they cite facts which contradict one another. The 

 "Pyocyanase-Immunproteidin" is a substance which possesses an 

 extraordinary bactericidal power, not only against the Bacillus 2^yo- 

 ^ Ztschr.f. Hyg., Leipzig, 1901, Bd. xxxvi, S. 9. 



