Anhydrous crystals of this substance are obtained by the action of ethyl alcohol on a solution of mercury nitrate according to the formula (see the article). They crystallize from a hot aqueous solution. This salt may be regarded as a salt of fulminate acid or of carbidoxime. The measured crystals were extracted from a dust-like powder, in which, however, due to the extraordinary luster of the microscopic crystals, shiny points are nevertheless visible, the luster is partly due to admixed droplets of mercury.