The term alkali is employed in a technical sense for the carbonate and hydrate (of sodium), but since in the Leblanc process the manufacture of sodium sulphate necessarily precedes that of the carbonate, we include this as well as the manufacture of hydrochloric acid which is inseparable from it.
Sodium sulphate, Na2S04, known in the hydrated condition (with ioH 2 O) as Glauber's salt, is manufactured in large quantities for conversion into the carbonate or soda (see Alkali Manufacture).
Guaiacol carbonate is known as duotal, the phosphate as phosphatol, the phosphite as guaiaco-phosphal; phosphotal is a mixture of the phosphites of creosote phenols.
Clearer evidence of their occurrence has, however, been found in fragments of wood fossilized by silica or carbonate of lime which are sometimes met with in coal seams.
In effect the urea first becomes carbonate of ammonia by a simple hydrolysis brought about by bacteria, more and more definitely known since Pasteur, van Tieghem and Cohn first described them.
Chalk consists, when quite pure, of calcium carbonate (CaC03), a white solid substance useful in small amounts as a plant foodmaterial, though in excess detrimental to growth.
The hydroxide or caustic soda, NaOH, is usually manufactured from the carbonate or by electrolysis of salt solution (see Alkali Manufacture).
Generally speaking the oxide or quicklime has a more rapid and greater effect in modifying the soil than slaked lime, and this again greater than the carbonate or chalk.
Magnesium Nitrate, Mg(NO 3) 2.6H 2 O, is a colourless, deliquescent, crystalline solid obtained by dissolving magnesium or its carbonate in nitric acid, and concentrating the solution.
Telluric acid, H2Te04, is obtained in the form of its salts when tellurium is fused with potassium carbonate and nitre, or by the oxidizing action of chlorine on a tellurite in alkaline solution.