VELOCITY OF REACTION. HOMOGENEOUS SYSTEMS 45 



With regard to the decomposition of tetanolysin in the 

 presence of acids or bases, some experiments executed by 

 myself gave the following results : 



On addition of equimolecular quantities of hydrochloric, 

 oxalic, citric, and tartaric acid (about 0.003 m l- normal), 

 the velocity of reaction was increased so much that the 

 decomposition of a i per cent solution of tetanolysin was 

 three-fourths accomplished in ten minutes. Of sulphuric 

 acid half this quantity was sufficient for the same purpose, 

 and for acetic acid a quantity seventy-five times as great. 

 The said concentrations all contain nearly the same quan- 

 tity of hydrogen ions, and it seems, therefore, probable 

 that this catalytic action is caused by the hydrogen ions. 

 Sodium hydroxide acts nearly as strongly as a strong acid 

 of the same molecular concentration ; but an ammonia so- 

 lution of the same concentration had a very little influence. 

 It was necessary to use it in about thirty times as high a 

 concentration as sodium hydrate to obtain the same effect. 

 Both these solutions have also nearly the same concentra- 

 tion of hydroxyl ions. 



With the aid of these experiences, it is very easy to in- 

 terpret a phenomenon observed by Ritchie. 1 He mixed a 

 -solution of tetanolysin with a small quantity of hydrochloric 



* Ritchie: Jaurn. of Hygiene, 1. 130 ( 



