activities are recorded in Table 1 as the velocity-coefficients of the 

 inversion, using minutes and decimal logarithms and multiplying by 

 10,000 to avoid decimals. The results are also expressed graphically 

 in figure 1 . 



It is apparent that alcohol has a strong inactivating action on 

 invertase even when the alcohol is dilute. The destruction of 

 invertase by alcohol does not take place below about 20 per cent, as 

 will be shown under the following caption, but the activity of the 

 enzym is markedly lowered by even a few per cent of alcohol. The 



10 20 30 40 SO 60 70 80 90 100 

 I/OLUME PERCENTAGE OF ALCOHOL. 



FIG. 1. The influence of alcohol on the activity of invertase. 



graph shows that the relation between alcoholic strength and activity 

 is not proportionality but may be represented as a logarithmic or 

 hyperbolic function. On account of the fact that rapid destruction 

 of the enzym takes place in solutions above 30 per cent alcoholic 

 strength it is not possible to measure the activity of invertase in this 

 region by the usual method; the theory of the modified procedure 

 which has accordingly been used to measure the activity in 50 and 70 

 per cent alcohol is given on page 6 and the values which were found 

 are included in the table and figure. 



[Cir. 58] 



