Ammonia
Ammonia is a gaseous compound of nitrogen and hydrogen which is extremely soluble in water. In liquid form it acts as a water-softener, and turns any grease with which it comes into contact into a soluble soap.
It is a valuable cleansing agent, usually used as a 10% solution in water. It removes loose dirt and grease, and effectively deals with some kinds of tarnish on silver. Ammonia should not be used on bronze as it attacks the metal. A little of the solution added to warm water makes an excellent cleanser for glass and porcelain, leaving the surface dirt-free and sparkling.
Ammonia solution has been successfully employed to free stonework of lichens and mosses. Strong ammonia solution is an effective varnish-stripper. Scrubb's Cloudy Ammonia is a 10% solution in water, and is a handy way of purchasing workshop requirements.