ANTITOXINS 1 9 



tate (globulins, nucleo-proteids, etc.) is treated with 

 saturated sodium chloride solution, practically all 

 the antitoxic fraction passes into solution. Gibson's 

 was the first really practicable method of concentrat- 

 ing the antitoxin. By means of it solutions of 

 antitoxic globulin could easily be made to contain 

 1500 units per cc. Continuing Gibson's work, 

 Banzhaf discovered that if the antitoxic serum or 

 plasma was heated to 57 for 18 hours, there was 

 a change of a considerable portion of the soluble 

 globulins (soluble in Nad solution) into insoluble 

 globulins. The antitoxin remained unchanged. 

 This procedure, therefore, permits of a still greater 

 elimination of the non-antitoxic proteids. 



Gibson has recently studied the possibility of 

 differentiating other antibodies by means of their 

 precipitation characteristics. He believes that a 

 differentiation of the antibodies into those precip- 

 itated with the pseudo globulins and with the 

 euglobulin fractions, according to the Hofmeister 

 classification, is based on a misconception of the 

 application of ammonium sulphate in separating 

 proteids by their precipitation characters. While 

 there seem to be some differences in the dis- 

 tribution of the antibodies in individual specific 

 sera in comparative experiments, this is not so 

 absolute as maintained by Pick l and others. Gib- 

 son's work on the fractionating of poly agglutina- 



1 Pick, Beitiage z. chem. PhysioL u- PathoL, VoL i, 1901. 



