INSECTICIDE AND FUNGICIDE BOARD. 655' 



of a paper which will be entitled " The Ai-senates of Calcium, II, 

 Equilibrium in the System Arsenic Pentoxide, Calcium Oxide, and 

 Water at 35° (Basic Section)." This paper will not be offered for 

 publication until certain check work can be performed. 



The investigations started about two years ago to determine the 

 active principles of two species of larkspur seeds {Delphinium con- 

 <iolida and I), sta'phisagria) have been continued. A method of 

 extracting and separating the oils and alkaloids on a considerable 

 scale has been developed, and considerable quantities of oil (free 

 from alkaloids) and of alkaloids have been separated. The oil is 

 now being tested against various species of insects and the chemical 

 and physical properties of the alkaloids are being investigated. 



The investigation begun some three years ago to determine what 

 changes commercial samples of calcium arsenate undergo during- 

 storage has been completed and the results published as Depart- 

 ment of Agriculture Bulletin No. 1115, entitled " Chemical Changes^ 

 in Calcium Arsenate During Storage." 



The study inaugurated some years ago to determine the rate of 

 loss of nicotine in potash-nicotine and soda-nicotine soaps and in 

 papers impregnated with nicotine and to determine the effect of 

 different types of containers on the rate of nicotine loss, the con- 

 ditions under which loss does and does not occur, and the conditions 

 that will prevent loss has been completed from the chemical point 

 of view. The results have been collated and studied and are now^ 

 being prepared for publication, if publication appears to be ex- 

 pedient. 



The study started about three years ago in regard to changes 

 on storage of commercial nicotine solutions, packed in different types- 

 of containers, and nicotine dusts, using various carriers and packed 

 in different types of containers, has been continued throughout 

 the year. Tliis work will be continued until definite conclusions- 

 can be drawn that will enable the board to handle cases involving 

 shortages in nicotine in nicotine solutions and nicotine filler dusts. 



It is often necessary to know the possible and probable rates at 

 which samples of chlorinated lime lose available chlorine in order 

 to be able to successfully prosecute cases based on shortage of avail- 

 able chlorine in commercial samples of chlorinated lime. In 1921 

 samples of most of the commercial brands of chlorinated lime sold 

 on the market were placed in storage and the changes in composi- 

 tion studied from time to time. During the past year samples of 

 known origin have been packed under commercial conditions by 

 board chemists and the changes taking place in such samples with 

 lapse of time are being studied. The data on this subject will be 

 offered for publication as soon as it is completed. 



Department of Agriculture Bulletin No. 795, entitled " The Adul- 

 teration of Insect Powder with Powdered Daisy Flowers," has been 

 revised and reprinted. 



The plant pathologists of the board have continued investigations 

 to determine more definitely the amount of active ingredients 

 necessary and safe for some of the more important types of fungi- 

 cides. This has included work principally on the various sulphur 

 and copper fungicides. In some sections lime-sulphur solution^ 

 used at standard strengths for the midsummer application on apples* 



