What is water glass?

Water glass, as the name implies, is soluble glass – a solution of silicate of soda. Sodium Siicate known as wate rglass  a thick, treacly, translucent substance prepared by fusing silica (sand and flint) with sodium carbonate. It can also be prepared under pressure using silica and caustic soda.

A familiar domestic use of water glass is in the preserving of eggs. They are left in a container of waterglass solution which coats the shell, thus preventing the entry of bacteria. It is employed as a protective coating on artificial stone for buildings to prevent weathering. Other uses are in soap manufacture and the making of fireproof cement.

You can also use it in the preparation of a chemical garden. To do this, make a mixture of one-quarter waterglass to three-quarters warm water. When this is cool, drop in one alum, one copper sulphate and one iron sulphate crystal. Within a few days they will grow coloured strands. These strands are composed of very small crystals.