300 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



is entitled "A Dosage Schedule for Citrus Trees with Liquid Hydro- 

 cyanic Acid." 



(Paper not presented for publication.) 



Chairman H. J. Quayle: The next paper is entitled "The Strati- 

 fication of Liquid Hydrocyanic Acid as Related to Orchard Fumi- 

 gation." It has been prepared by Mr. R. S. Woglum and M. B. 

 Rounds both of the Bureau of Entomology and will be presented by 

 Mr. Rounds. 



THE STRATIFICATION OF LIQUID HYDROCYANIC ACID AS 

 RELATED TO ORCHARD FUMIGATION 



By R. S. Woglum and M. B. Rounds, Bureau of Entomology, 

 Department of Agriculture, Alhambra, Col. 



The use in orchard fumigation in California of liquid hydrocyanic 

 acid sometimes containing a large per cent of water has brought forth 

 the question "Does this chemical ever stratify?" The prevalent 

 opinion among those who have worked most with this active agent 

 appears to be that stratification is improbable even when liquid 

 hydrocyanic acid of widely different strengths or even liquid hydro- 

 cyanic acid and water are brought together in any proportion, and 

 this view, at first, was accepted by the writers. The definite assertion 

 to the senior writer by Mr. S. A. Stowell, an experienced fumigator, 

 that he had drawn water and hydrocyanic acid from the same drum 

 led to the outlining of a series of experiments in an endeavor to settle 

 this point. 



The first experiment which was performed by Mr. H. D. Young by 

 slowly bringing together liquid hydrocyanic acid and tap water gave 

 definite stratification. This preliminary experiment was followed by 

 many others during which liquid hydrocyanic acid was added to tap 

 and distilled water and vice versa; also liquid hydrocyanic acid of 

 widely separated purities were brought together. In this work glass 

 bottles were used each first being half-filled with material to which 

 the second liquid was added slowty by means of a pipette. The bottles 

 were not shaken. Typical experiments are herewith presented in 

 brief. 



In each of these eleven experiments stratification occurred regardless 

 of the order in which the different liquids were added; the effect was 

 similar whether the water was added to the hydrocyanic acid or the 

 hydrocyanic acid to the water. Distilled water reacted in a manner 

 similar to tap water. Each of these experiments was repeated and 

 many others of like nature were performed. In every instance in 



