VELOCITY OF REACTIONS 



37 



question have been made "in vitro." In 1885 

 E. SCHUTZ added different amounts of pepsin to 

 solutions of a given quantity of egg-albumen. The 

 mixture was then diluted to 100 cc. and kept at 

 37-5 C. for sixteen hours. After this the albumen 

 was removed and the quantity of its product of 

 decomposition, peptone, determined polarimetrically. 

 SCHUTZ found that this quantity x is proportional 

 to the square root of the quantity q of pepsin added. 

 His experiments were repeated by JULIUS SCHUTZ 

 in 1900. He determined the quantity of peptone as 

 proportional to the quantity of nitrogen remaining 

 in the solution after coagulation of the albumen. 

 His results are seen from the following table : 



As is seen from the diagram (Fig. 7) representing 

 the so-called " SCHUTZ'S rule," which says that the 

 action is proportional to the square root of the 

 quantity of enzyme, this rule is only approximatively 

 true. At higher values of q the digested quantity 

 x falls short of the one calculated in accordance 

 with the rule. 



In 1895 SJOQVIST made a very elaborate in- 

 vestigation on peptic digestion. He varied both 

 the quantity of pepsin and the length of time. 

 The temperature was 37 C., i.e. that of the human 



