tjie Analyses of M. Kl-aproth. 343 



Tl-.e natrum of Esn^'p^j when well freed from the earthy 

 parts mixed with it, is composed of 



Dry carbonate of soda - - 163 



Dry sulphate of soda - - 104 



Dry mm-iate of soda - - 75 



Water ♦ - - - 158 



500 



yiiiahjsis of the radiated Natrum o/Trona. 



The natrum of Egypt is often found in very hard crystal- 

 line masses : it is iiidcbted for its hardness to the muriate 

 of soda, which is generally combined with it : so great is 

 its hardness, that it has been even employed in constructing 

 the w alls of Fort Ouasir. 



That of Dcbrezin in Hungary, and of Monte Nuovo 

 near Naples, having, on the other hand, lost its water of 

 crystallization, is found only under the form of dust. 



Radiated natrum is not subject to effloresce, though 

 formed in the hottest climates of Africa : this phsenomenon 

 will be explained by the analysis hereafter given. The fol- 

 }o\%in2; is the description of this remarkable kind of natrum 

 by INLBaggc, the Swedish consul at Tripoli : 



' " It is found at a place called Trona, in the province of 

 Sukena, two days journey from Fessand, at the foot of a 

 rockv mountain, where it forms a crust of an inch in thick- 

 ness at most, and sometimes of only a few lines : it is al- 

 ways crystallized : its fracture exhibits long crystals, agglu- 

 tinated,' parallel, and sometimes radiated : it resembles un- 

 calcined plaster. Besides a large quantity of Trona, a nauie 

 it has received from the place where it is found, which is 

 carried to Negroland and Egypt, a thousand quintals of it 

 arc carried every year to Inpoli. It is not mixed with 

 ' muriate of soda; and the gait mines arc on the sea coast, 

 f..\ cniy-eight miles from Trona, which is situated in the 

 interior of the country." 



The natrum employed by M. Klaprolh in his analysis form^J 

 a crystalline crust of from four to six lines in thickness, com- 

 i)(.v-ed of vertical lamime of a foliated and radiated texture. 



The natrum of Tripoli, according to analysis, contains 

 Water of crystallization " - i2L"50 

 Carbonic acid - - 38*00 



Pure soda - - - 37*00 



Sulphate of soda - - 2-00 



99-50 

 Y4 If 



