The first portion of the distillate brings over the gases dissolved in the water, ammonia and other volatile impurities, and is consequently rejected; scarcely two-fifths of the entire quantity of water can be safely used as pure distilled water.
The Arabians greatly improved the earlier apparatus, naming one form the alembic; they discovered many ethereal oils by distilling plants and plant juices, alcohol by the distillation of wine, and also distilled water.
A small stool is then placed over the balance pan, and on this is placed a beaker of distilled water so that the solid is totally immersed.
The solutions are made by dissolving the purest recrystallized sulphate of copper and sulphate of zinc in distilled water.
Its weight is so adjusted that an additional weight of 5 grammes must be placed in the upper pan to cause the instrument to sink to the mark on the stem in distilled water at the standard temperature.
