Ustilago, and filling a greenhouse with hydrocyanic acid gas when young insects are commencing their ravages, e.g.
Carbolic acid is distinguished from all other acids so-called - except oxalic acid and hydrocyanic acid - in that it is a neurotic poison, having a marked action directly upon the nervous system.
This compound combines with hydrocyanic acid to form a nitrile which hydrolyses to dichlorhydroxy iso-butyric acid.
Instances had already been recorded of cases where a halogen element replaced hydrogen with the production of a closely allied substance: Gay Lussac had prepared cyanogen chloride from hydrocyanic acid; Faraday, hexachlorethane from ethylene dichloride, &c. Here the electronegative halogens exercised a function similar to electro-positive hydrogen.
Cyanogen and hydrocyanic acid, recognizable by their odour, indicate decomposable cyanides.