there was then added 0.5 ec. of a solution of aloin in 10 per cent chlo- 
ral hydrate. (1) remained yellow in color. ( 2 ) became wine red. and 
(3) also became wine red in color, but more slowly than ( 2 ). These 
results tend to confirm the work of Schaer on the use of aloin as a 
reagent for the plant and animal peroxidases. At the same time they 
go to show that the delicacy of this test for the plant peroxidases 
depends very largely on the concentration of the hydrogen peroxide, 
and that as a rule much better results are obtained by the use of small 
amounts of the peroxide. On the other hand, with the peroxidases of 
the animal tissues larger amounts of the hydrogen peroxide can be 
employed with good results. 
