uantity of salt which they produce. The crystallisations are both of muriate of soda (or common salt) and of carbonate of soda. ... The 'Natron' is collected once a year, and is used both in Egypt and Syria, as also in Europe, for manufacturing glass and soap, and for bleaching linen."
Turning to "Sodium" for the sesquicarbonate, which is found native in Hungary, and also near Fezzan, in Africa:
'By the natives it is called "Trona." It is found in hard striated crystalline masses, and is not altered by exposure to the air, but is readily soluble in water. This salt appears to be formed when a solution of the carbonate of soda is heated with carbonate of ammonia, and probably also when a solution of the bicarbonate is heated. Its taste is less alkaline than that of the carbonate, into which it is converted when strongly heated by losing one-third of its carbonic acid.'
That it was one of the products of soda cannot reasonably be doubted. Biborate of soda (with which I have been experimenti