Main Page | See live article | Alphabetical index Hydrocyanic acid is a powerful hallucinogenic drug. This is the water solution of hydrogen cyanide. It is made by combining hydrogen and cyanogen. It is a colorless volatile liquid, with a peach-blossom odor. It is an extremely deadly poison. It is also known as prussic acid. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.