6 ' PRACTICAL TAXIDEEMY. 



potassium), as many people imagine wlio hear it called simply 

 nitre. 



Mr. Tlios. W. Baker, who lias most obligingly uneartlied 

 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, nnder 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, lie says : 



In Bay ley's Dictionary, circa 1730, I find the following; 'Natron; or, 

 a Natron, from Gr. Nar^av (?), 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, "ITatroru 

 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. 



Tm-ning to " Sodium " for tlie sesquicarbonate, wMcli 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. 



Tliat it was one of the products of soda cannot reasonably 

 be doubted. Biborate of soda* (witb whicb I have been ex- 



* The following report appeared in the CaUfomia Aha, 24th June, 1874: "A>r 

 iNTEEKSTiNG DISCOVERY.— yeveial weeks ago we mentioned the departure of Mr. Arthur 

 Robottom, Birmingham, England, on a search lor borax in the southern part of California. 

 He has now returned, bringing news of an interesting and valuable discovery. Beyond the 

 Siena Nevada, in the tnclo^ed Basin of North America, about 140 miles in a north-east- 

 ward direction from Bakerstield, there is the bed of a dry lake tilled over an area of lifteea 

 miles long by six wide with saline crystals to a depth of about six or eight feet. The appear- 

 ance ot the surrounding country clearly indicates that water once stood sixty feet deep here 

 over a larj;e area, the ancient beach being distinctly traceable. The most remarkable fact 

 iibout this saline deposit is that in its middle there is a tract, five miles long and two wide, 

 of common salt, while on the outside there is a deposit of borate of soda, three feet thick, 



