[Vor. 5 
268 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
The substrates were all made up in 1 per cent aqueous 
solutions with the exception of the starch solution and the 
olive oil emulsion. Casein was dissolved in sodium hydrate 
and then made up to volume with water. The preparation of 
the starch and oil substrates has been outlined by Zeller (716), 
but the details are here repeated for those to whom his paper 
may not be accessible. 
Five grams of soluble starch were added to 300 cc. of dis- 
tilled water and while constantly stirred brought to boiling. 
This was added to a flask of two liters capacity containing 
1200 ec. of hot distilled water, and the contents then boiled 
with a reflux condenser for 2 hours; when cool the solution 
was made up to 2 liters, plus 1 per cent toluol as antiseptic. 
The above constitutes what is known as a 1 per cent solution. 
The method for making the olive oil emulsion is one which 
Davis (715) and Zeller (716) ascribe to Bloor, but the writer 
has been able to find no description of it by the latter in the 
literature, and it is therefore taken from the sources indi- 
cated. The procedure was as follows: Twenty ce. olive oil 
were dissolved in hot absolute aleohol. 'This was placed in a 
hot funnel, the tip of which had been drawn out to a very fine 
bore, and the hot solution of oil in aleohol passed drop by drop 
into 200 ee. of cold distilled water which was vigorously 
stirred throughout the process. The resulting milky emulsion 
was then boiled to expel the aleohol and upon cooling made 
up to 1 liter with distilled water. 
The extraeted enzymes of the first series (lots A and B) 
were dispersed in such a volume of doubly distilled water that 
0.8 ec. of solution represented 1 gm. of fresh tissue. In the 
second series (lots C and D), loss by accident of one-half the 
dispersion just previous to use necessitated its dilution to 
half the strength of that in the first series. Ten cc. of dis- 
persion in each case were added to 50 ce. of substrate in 
Erlenmeyer flasks of 125 ce. capacity, with 0.5 ce. toluol as 
antiseptie. For controls 10 cc. of distilled water per flask of 
substrate were substituted for the volume of enzyme. Com- 
parison was also made between active and inactivated enzymes 
by a parallel series of substrate flasks containing equal 
