ANNUAL REPORT, 1940 35 



other extreme, i.e., water; but new growth must wait until a new set of 

 roots is produced. Literature intimates that there is a difference in roots 

 in different media, but there is no information in regard to just what the 

 difference is. A study with the microscope may reveal certain differences 

 of structure. 



The Nature of an Oxidant in a Nutrient Solution. (L. H. Jones, C. A. 

 Peters, and W. B. Shepardson. Cooperative with Chemistry.) When the 

 solution of a soybean plant culture is covered by a mineral oil film, an 

 oxidant is produced in the solution that can be quantitatively determined 

 by the Micro-Winkler method for the determination of dissolved oxygen. 

 The oxidant is not O2; it is cumulative in the solution but not cumulative 

 in the plant; it is produced by a living plant but not by a dead plant; the 

 small amount of nitrites sometimes associated with it does not interfere 

 with the quantitative determination. 



If, in determining the oxidant by the Micro-Winkler method for oxygen, 

 the sample is allowed to stand for a half hour after it is ready for titration, 

 no returning end point is obtained. However, if the sample is titrated 

 immediately, the end point is indefinite and continuing. This end point, 

 if continued, will eventually come to the same figure as obtained after the 

 half hour wait. The production of this oxidant by a plant is not understood 

 and its composition is unknown. Some facts about its action under various 

 conditions may aid in determining more exactly the nature and substance 

 of this particular oxidant. 



DEPARTMENT OF CHEMISTRY 

 W. S. Ritchie in Charge 



Cooperative Analytical Service. (The Department.) Thirty-four samples 

 of blueberry bushes raised in the greenhouse in sand cultures by the 

 Pomology Department were sent to the laboratory to determine their 

 response to various nutrient solutions. The yield of air-dry leaves was 

 determined in all cases, and the percentages of nitrogen, crude ash, and 

 iron in dry matter in 13 composites. The yield in several instances was so 

 small that further investigation was not possible. Freezing-point deter- 

 minations were made on ten of the nutrient solutions as a measure of con- 

 centrations. 



The manganese, calcium, and phosphorus were determined in a poultry 

 ration as well as in the calcite added to it. The manganese in the egg 

 (shell and yolk) was also determined as part of the study to evaluate the 

 role of this element in the life processes of the chicken. Details of this 

 work will appear under the report of the Poultry Department. 



Spray materials. Several samples of spray material were submitted 

 for analysis, including two lots of nicotine, fish-oil soap cartridges used for 

 the control of aphis, which tested 6.79 and 5.83 percent of nicotine re- 

 spectively. The soap in both instances was fairly soluble and left but 

 slight residue. 



A sample of so-called Fruitone, which is applied as a spray to retard 

 apple drop, was received from the Pomology Department. This was a 

 fairly soft white powder used at the rate of 1 pound to 200 gallons, and 

 consisted of about 54.50 percent of talc (spreader) aiid 39.50 percent of 

 organic acids (as citric by titration), together with some hygroscopic 

 moisture and a small percentage of declared naphthalene compounds. 



