BACTERIAL P K < > T K I 1)S. J I 



BRVe peptone were employed. In this ca-e they -iipp 

 that the bacteria reconvert (lie peptone into :m ;illiiiiiii). 



The poisonous proteids obtained by BRIEQEB MIK! 

 Ki: \NKKL from cultures of the Kin-rill germ, the comma 

 bacillus, and the staphyloeocciis ann-ns art- practieally in- 

 soluble in \valrr, and more nearly related to (he globulins 

 than (he albumins, although (hey dill'er from the former 

 in their tardy and difficult solubility in dilute solutions of 

 sodium chloride. 



The poisonous protcids isolated by VAUGHAN from cul- 

 tures of two species of toxico^enic licrins found in drinking 

 water, supposed (o IM- (he cause of (yphoid fever, an> solu- 

 ble in water, from which they an- not precipitated by lx>il- 

 iiiLi, or by concentrated nitric acid, or by both. Potassium 

 (errocvanide and acetic acid, sodium sulphate, magnesium 

 sulphate, and carbonic acid also liiil to precipitate them. 

 They are precipitated by the general alkaloidal reagents, 

 and respond to the xanthoproteid, Millon, and binret (cs(s. 

 They are precipitated by ammonium sulphate when added 

 to saturation, and for this reason cannot be classed amon<; 

 the peptones. Neither l>en/oyl chloride nor phenyl-hydni- 

 /in chloride precipitate them. Their poisonous properties 

 are destroyed by prolonged boiling or l>\- bein^r hea(<'<l to 

 S() for some hours, though they remain active after an 

 exposure of (<-n minutes to the last mentioned temperature. 



Of the three bacterial proteids obtained by the same ex- 

 perimenter from the bacilli x, a and A of Booker's list of 

 summer diarrlnea .irerms, the first two are soluble in water, 

 while the other is not. So far as their behavior with pre- 

 cipitating agents is concerned, the first two agree with the 

 proteids of the water ^erms. 



TI/XOM and CATTANI find that the proteid of cultures 

 of their tetanus germ is rendered inert by precipitation with 

 absolute alcohol. It is obtained by saturation with am- 

 monium sulphate, and the removal of the silt by dial\ >i-. 



Further description of the individual proteids will le 

 in subsequent chapter-. 



2* 



