SDPPtTRATlOJSr. 129 



death shows the same changes which are observed in the 

 diphtheritic nephritis of children. Babes also finds that 

 the germ-free cultures produce the parenchymatous degener- 

 ations of the internal organs which are found in the human 

 body. 



Tangl has shown that the chemical poison is formed in 

 the body as well as in culture-flasks. A large piece of 

 pseudo-membrane was macerated in water in an ice-chest 

 for twenty-four hours, and then filtered through porcelain. 

 The filtrate, injected into animals, producetl all the symp- 

 toms which have been obtained by a similar employment of 

 artificial cultures. Tangl also observed that in some cases 

 in which the animals were inoculated with the sterilized 

 culture through the mucous membrane a pseudo-membrane 

 formed at the point of injection. 



Suppuration. — As early as 1879, Leber concluded 

 from his observation on infective keratitis that the asper- 

 gillus must produce certain soluble products which diffuse 

 through the cornea and set up an inflammatory action in 

 the adjacent vascular tissue. In 1882, he showed that sup- 

 puration could be induced by the introduction of sterilized 

 mercury and copper, and that the pus formed is free from 

 germs. In 1884, he induced suppuration by the injection 

 of cultures of the staphylococcus pyogenes aureus which 

 had been sterilized by being boiled for hours. In 1888, 

 the same investigator reported that he had found an alco- 

 holic extract of the dried staphylococcus to be highly pyo- 

 genetic. From this extract he has prepared a crystalline 

 body which he calls phlogosin. This substance is readily 

 soluble in alcohol and ether, sparingly soluble in water, 

 and it crystallizes in needles. The crystals can be sub- 

 limed, leaving no residue, and the sublimate, which forms 

 in rosettes, still possesses the pyogenetic properties. Alkalies 

 precipitate this substance from its solution in amorphous 

 granules, which dissolve in acids, forming crystalline salts. 

 Leber refers to the observation of the botanist Pfeffer, 

 who found that vegetable cells are attracted by certain 

 chemical substances, and adopts the term chemotactic action 



