VELOCITY OF REACTION. HOMOGENEOUS SYSTEMS 59 



A very good instance is given by Henri l of the in- 

 version of cane sugar by means of invertase at constant 

 concentration. The following table gives the number (n) 

 of milligrammes inverted during the first minute of solu- 

 tions of cane sugar of the concentration, c. normal ( i normal 

 = 342 g. per liter). 



c = o.oi 0.025 o< 5 Otl - 2 5 -5 l l *S 2 

 n = 0.58 1.41 2.40 2.96 4.65 5.04 4.45 2.82 1.15 



As will be seen from these figures n is at first nearly 

 proportional to c, then it reaches a maximum at c = o.5, only 

 later on to sink again at very high concentrations, at 

 which the solvent may be regarded as changed. 



In good agreement with this experience Terroine found 

 that the quantity of maltose transformed by means of a 

 given quantity of maltase in a 100 c.c. of solution is nearly 

 proportional to the concentration of the maltose until it 

 reaches about 2 per cent and is thereafter independent of the 

 concentration. This regularity may be detected in some 

 experiments executed by Tammann as early as in 1889, on 

 the decomposition of different quantities of amygdalin 

 by means of a constant quantity of emulsin. 2 All these 



DECOMPOSITION OF AMYGDALIN (IN GRAMMES) BY MEANS OF EMULSIN 



Quantity of amygdalin 2 -555 5- 11 10.229 



Time (min.) = 14 0.61 0.61 0.50 



19 0.77 0.85 0.73 



23 0.79 0.98 0.86 



experiments lead us to the assumption that the substance 

 which really is decomposed into the reaction-products is in 



1 Henri: "Lois generals de 1'action les disastases: These," Paris (1899). 



2 Tammann : Zeitschr. f. ph. Ch. 3. 33 (1889) ; Hoppe Seylers Ztitschr. 16. 

 315 (1892). 



