— 174 — 



The principle question treated in this paper is : Does the 

 brain contain a ferment capable to break down the nucleic acid 

 which arises from the nucleo-proteid , during autolysis , by the 

 action of the proteolytic ferments ? 



I have found it also useful to extend my researches both 

 to proteolytic ferments and ferments capable to split up the 

 phosphatides. 



For these researches were employed brains of dogs which 

 had been subjected to autolysis immediately after being killed. 

 Chloroform was used as an antiseptic and the autolysis took place 

 at 37° for 96 hours. 



IL — Methods. 



Before describing each experiment separately 1 shall give 

 here the general outlines of the methods adopted both for the 

 research of ferments as well as for the chemical analysis. 



Dog's brains were selected for these experiments. 



As soon as the animai was killed the brain was immediately 

 freed from its adhering membranes and from blood, then poun- 

 ded in a mortar until the whole had become a homogeneous 

 paste. ■ 



In a few experiments the dry residue, ash, organic matters, 

 total nitrogen and total phosphorus were estimated in the brain- 

 paste thus obtained. 



For the research of ferments a certain quantity of brain-paste 

 was mixed, in a glass-stoppered-bottle, with ten times its bulk of 

 chloroform-water adding besides some pure chloroform , then 

 well shaken. This mixture constitues the main-research which, 

 for abreviation, shall be designated by the letter A. Besides this 

 mixture there has always been made a second consisting of the 

 same quantity of brain-paste mixed with ten times its bulk of 

 water and acidified with a few drops of diluted acetic acid. This 

 mixture was heated to boiling point to destroy the ferments, 

 When cool it was poured into a glass-stoppered-bottle of the 

 same size as that employed for mixture A, then some pure chlo- 

 roform was added and the whole was well shaken, This mixture 

 constitues the control-research which , for abreviation , shall be 



