32 MISSOURI AGR. EXP. STA. RESEARCH BULLETIN NO. 21 



4a and 4&. 5 gr. heated cortex from untreated twigs plus castor 

 oil emulsion. 



5a and 5b. 25 cc. castor oil emulsion only. 



One cc. of toluene was added to all vials. The material was 

 allowed to act at 35 C. for from ten to twenty-four hours. At in- 

 tervals, some of the liquid in each vial was removed and tested for 

 acidity by adding neutral litmus. In other cases, a few drops of 

 phenolthaline were added to some of the liquid from each vial and 

 then, drop by drop, weak NaOH was also added until the red color 

 appeared. The material requiring the largest amount of NaOH, 

 i. e., that which produced most acid, was considered to be most 

 active so far as fat splitting enzymes were concerned. 



In all cases tried, the etherized material was most active in 

 producing fatty acids. The ash material was more active than 

 the apple. 



4. Oxidising Enzymes. The work of the oxidising enzymes as 

 influenced by the rest period breaking agents was observed thruout 

 the season. The COz determinations, to a large extent at least, 

 express the activity of the oxidases. However, the work of these 

 ferments can be detected in other relatively simple ways. The 

 browning of the exposed flesh of apples is familiar to all. This 

 browning is due to an oxidase (maloxidase). Similarly Kastle 1 has 

 demonstrated that the browning of freshly cut vegetable tissue 

 which is exposed to air, is due to oxidases. The following experiment 

 shows more specifically what may be expected in case of cortex 

 material, and it also demonstrates the reliability of using this color 

 change as a basis for judging the activity of oxidizing enzymes. 



On February 8, 1914, some Wolf River apple twigs were col- 

 lected. The cortex was scraped from these twigs and ground up 

 finely. After mixing this material, a number of duplicate 5 gr. 

 samples were weighed out, and treated in the following manner: 



(A) Two lots in the open air without further treatment. 



(B) Two lots in an atmosphere of ether. (Ice. per L.). 



(C) Two lots heated to 100 C., then placed in open air. 



(D) Two lots heated to 100 C., then placed in ether atmos- 

 phere. 



At the end of one hour, all lots were removed to the open air. 

 Lots A were somewhat brown. Lots B were very dark brown. 

 Lots C and D were a similar green, showing no change in color. 



1. Kastle, J. H. The Oxidases. Bull. 59, Hyg. Lab., U. S. Pub. Health 

 & Mar. Hosp. Serv. Wash. 



