VELOCITY OF REACTION. HOMOGENEOUS SYSTEMS 69 



indicates that the method of Sjoqvist was very useful and 

 even that the theoretical views are rather concordant 

 with the facts. It would have been desirable to have 

 varied the quantity of hydrochloric acid in these experi- 

 ments. Some experiments of Sjoqvist on the digestion 

 in the presence of other acids than HC1, namely, sul- 

 phuric, nitric, and phosphoric acid, seem to indicate that 

 the action of these acids is (about 16, 24, and 37 per cent 

 respectively) less than that of hydrochloric acid ; but more 

 empirical material is desirable before definite conclusions 

 may be induced. 



E. Schiitz and Huppert l have made a large number of 

 measurements of the digestion of egg-white by means of 

 hydrochloric acid and pepsin. The egg-white was freed 

 of globulins. The influence of the concentration of acid 

 was such that if i g. of egg-white in 100 c.c. was digested, 

 the digested quantity in a given time increased with the 

 quantity of acid, but more slowly than proportionally to this, 

 until its concentration was 0.2 percent; thereafter it was 

 nearly constant, or in some cases, even decreased a little. 

 This agrees with the opinion that the really reacting sub- 

 stance is the albuminat-ion, but further investigations are 

 necessary before this may be stated with certainty. 



In another series of experiments the temperature was 

 varied. The digested quantity of 0.922 g. egg-white in 

 100 c.c. of 0.2 per cent HC1 was found to be : 



At 30 C. 0.544 g. = 59.0 per cent Calc. 59.0 per cent 



" 35 " 0.660 " 71.6 " " 71.4 " 



" 27.5 0.713 77.3 77.4 



" 40 " 0.775 " 8 3- " " 83.0 



1 Schutz and Huppert : Pfliiger's Arcbiv. 80. 470 (1900). 



