HYDROGEN CYANIDE FUMIGATION 



CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 249 



E. E. Clayton 



(with TWO figures) 



The object of this work was to secure data on the manner in 



which green plants are affected by exposure to hydrocyanic acid; 



with particular emphasis on the resistance of the plants to this gas 



and the modification of this resistance by various factors, external 



and internal. A number of articles have been published concerning 



the effect of cyanide on animals. More recently its action as an 



enzyme paralyzer has been brought forward prominently. 



Information as to the action of cyanide on plants is of scientific 



interest, and certainly of practical value, for hydrocyanic acid finds 



important use as an insecticide in orchard and greenhouse practice. 



Circumstances have forced the discontinuance of this work, with 



many phases of it incomplete, but enough facts have been estab- 



Hshed, and enough new lines suggested, to warrant its pubh'cation 



in this incomplete form. 



Historical 



Literature bearing on this problem is not abundant. The 

 Department of Agriculture and several of the experiment stations, 

 notably the CaUfornia station, have pubHshed a number of bulletins 

 dealing with fumigation as a commercial process; but the work done 

 is of a kind which assists little in answering the fundamental physio- 

 logical questions involved. The action of cyanide on the animal 

 and in connection with various chemical processes has been 

 thoroughly investigated, and from a consideration of these data we 

 can gain much. 



ScHONBEix (8) first called attention to the inhibitory effects of 

 hydrocyanic acid. He worked with the leaves of plants, and also 

 with animal blood, and found that the presence of the acid prevented 

 each of these materials from decomposing hydrogen peroxide. He 

 concluded that the extremely poisonous action of cyanide on the 



483 



