2O4 PREPARATION OF PEPTONES 



37 C., is determined. The deviations are noted at 

 certain intervals. If there is no change in the 

 deviation, then we conclude that no decomposition 

 has taken place. Should there be an alteration in the 

 rotation after some time, then we must infer a 

 fermentative decomposition, such as has been demon- 

 strated by special experiments with ferment solutions. 

 We shall now give a description of the preparation 

 of the peptone. 



PREPARATION OF PEPTONES FOR USE IN THE OPTICAL 



METHOD. 



Organs are first deprived of their blood, in exactlv 

 the same way as has been described on p. 164. 

 They can then be subjected directly to hydrolysis, 

 after the pieces of tissue have been dried, as much as 

 possible, between filter papers. If it is desired to 

 collect larger quantities of the same tissue, then the 

 tissue, freed from blood, is boiled for ten minutes in 

 water, and is subsequently preserved in sterilized 

 water with chloroform and toluol. It is, of course, 

 not necessary, in this case, to boil the organ to 

 such an extent, as to deprive it of all substances 

 reacting with ninhydrin. Boiling is merely resorted 

 to here, in order to destroy any cell ferments that may 

 be present; otherwise autolysis may manifest itself. 

 As soon as enough of the organ has been collected, 



