:ji c A u T 2 o N :'.'. 



Cyanides are deadly poisons. Deatli can result from swallow- 

 ing small amounts of the salts or the acid and from breathing 

 low concentrations of the gas, hydrogen cyanide. When sodium 

 cyanide is added to water, hydrocyanic acid is produced and a 

 small amount is evolved at the surface as hydrogen cyanide. It 

 is conceivable that under certain conditions enough gas could 

 accumulate to be dangerous. The greatest dangers are accidental 

 ingestion of the salt and inhalation of the gas released by the 

 action of an acid that has been allowed to come in contact with 

 sodium cyanide. Sodium cyanide should be used only by tech- 

 nicians acquainted with it . 



At the low concentrations of sodium cyanide used for fish re- 

 moval, there is little danger to domestic animals as a result 

 of drinking the treated water . Mammals would have to drink 

 from two to three times their body weight to receive a lethal 

 dose . The writer observed no noticeable effect on a herd of ponies 

 that obtained their principal supply of water from a pond that had 

 been treated with 1 p. p.m. sodium cyanide. 



