Now, as ( Nitron) is more likely, from its etymology, to be translated "nitre," we are landed into another difficulty, if by nitre we mean saltpetre, for that will, as we all know, preserve animal tissue for a certain time; however, I do not think we can translate natron as being nitre (saltpetre), for in former days many salts were included under the general term nitre; for instance, our common soda and potash, the chemical composition of which was unknown until Davy, in 1807, extracted the metals sodium and potassium from those salts. Boitard expressly states:
"Il parait que ce natrum était un alkali fixe, et pas du tout du nitre comme quelques auteurs l'ont pensé; ce qui semblerait appuyer cette opinion, c'est que lea femmes egyptiennes se servaient de natrum pour faire leur lessive, comme on as sert aujourd'hui de la soude."
In Peru the soil may be said to be impregnated with nitre, but that is nitrate of soda, and not really saltpetre (nitrate of potassium), as many people imagine who hear it called simply nitre.
Mr. Thos. W. Baker, who has most obligingly unearthed several old works for me, says:
"Now I think of it, natron is perfectly familiar to me as apparently a mixture of broken soda crystals and a brown earth which is sold in the bazaars of India, under the name of 'sootjee moogee,' for domestic purposes; and I know, from experience, that unless it is washed off paint work directly it is passed over it with a cloth all the paint comes off bare, sometimes to the wood."
Again, he says:
"In Bayley's Dictionary, circa 1730, I find the following: 'Natron; or, a Natron, from Gr. Natron (?) ( Natron), a kind of black greyish salt, taken out of a lake of stagnant water in the territory of Terrana, in Egypt."
Also see "Penny Cyclopaedia," vol. xvi., p. 105, "Natron, native sesquicarbonate of soda (see 'Sodium'):"
"The Natron Lakes, which are six in number, are situated in a valley bordering upon Lower Egypt, and are remarkable for the great quantity 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: