Hexamine: Formaldehyde Vapour into Strong Ammonia Water, Wohl's Method

Formaldehyde vapour led into strong ammonia water combines with it into hexamethylenetetramine (hexamine); boiled down to a syrup and poured into alcohol, it crystallizes (Wohl 1886, in Thorpe 1912). Hexamine dissolves readily in water. When heated it gives off formaldehyde, which is why it hardens Bakelite. The picture: hexamine crystals (photo by Milda 444, Wikimedia Commons, CC BY-SA 4.0).