Important: Safety Warning
This page contains a formula or preparation using substances now known to be dangerously toxic, such as arsenic, mercury, lead, or cyanide compounds. Exposure to these substances can cause severe poisoning, permanent injury, or death.
This information has been left in for historical purposes but should not be acted upon.
Cyanides
chemical compounds which contain the monad radical (CN)', combined with a metallic element, as K (CN)', potassium cyanide, or with a hydrocarbon radical, as CH2. (CN) methyl cyanide. Cyanides can be obmixtained synthetically by heating a mix- ture of potassium carbonate and charture of potassium coal to redness in a porcelain tube, and passing nitrogen gas through the tube.
Also formed when an organic body containing nitrogen is heated in a tube with metallic sodium. If cyanides are dissolved in water rendered alkaline by potash or soda, then a mixture of ferrous and ferric sulphates is added, and the mixture is rendered acid with dilute hydrochloric acid, a blue color of ferrocyanide of iron being formed. If the liquid containing a cyanide be made acid with a few drops of hydrochloric acid, and then a little yellow ammonium sulphide be added, and the liquid gently evaporated till the excess of sulphide is volatilized, the residue will give a red color when a few drops of tincture of iron are added. Cyanides give a curdy CYCLOMETER white precipitate with silver nitrate, which is insoluble in cold nitric acid, the dry precipitate, Ag (CN)', when heated in a small glass tube, giving off cyanogen. Cyanides may be formed by dissolving metallic oxides or hydroxides in a solution of hydrocyanic acid, H.CN, also by double decomposition of metallic salts, with potassium cyanide if the resulting cyanide is insoluble.