Hydrolysis of cane sugar by saccharase

of water, a few drops of toluene are added, and the mixture is left for fifteen hours at about 30° to allow the enzyme to be set free. 

In order now to remove proteins from the thin sludge it is vigorously stirred with 0-05 A-acetic acid in amount just sufficient to change the colour of methyl red (pH=4) (test with a sample), and is then filtered as above after shaking with a little kieselguhr if necessary. The filtrate is made neutral to litmus with dilute ammonia and in this condition, protected by a little toluene, can be kept unchanged for several days. 

The main solution in which the reaction goes on is kept at 30°. From it samples are taken for polarisation every twenty minutes during the first hour after the beginning of the experiment, and every thirty minutes during the second hour. During this reaction period that stage of the inversion which is shown by zero rotation is usually passed. This indicates that about 75 per cent of the cane sugar taken has been hydrolysed. 

When the rotations are plotted as ordinates against the times as abscissae, the observed points can be connected by a logarithmic curve, which is flatter in the later stages of the reaction and indicates the order as unimolecular. The abscissa of the point in this curve corresponding to a rotation of 0° gives the zero-rotation time , which is to some extent a measure of the activity of the enzyme solution employed. 

The course of the curve already indicates that the logarithmic law is not strictly obeyed. By exterpolation we can obtain the point of 

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