Liquid ammonia

NH4OH. Pungent smelling, light and irritating alkaline liquid obtained by dissolving gaseous ammonia in water. The specific weight of the liquid ammonia falls as the proportion of gas increases (10% gaseous ammonia = 0.96; 30% = 0.9). Liquid ammonia is used to smoke woods containing tannin, where nice, grey-brown colour tones are achieved. The addition of liquid ammonia causes the stain to penetrate deep into the wood fibres as well as enhancing the colour tone