258 CLARKE 



Analcite NaAlSijOfi.HjO. 



Ammonium analcite NH^AlSioOg. 



Silver analcite AgAlSisOg.HjO. 



Thallium analcite TL\lSi206. 



Strontium analcite SrAl^Si^Ojo. 



Barium analcite BaAljSi^Oij. 



The ammonium, silver and thallium compounds, prepared by 

 Mr. Steiger, are all very definite and stable. They were 

 formed by heating analcite with ammonium chloride to 350°, 

 or by fusing analcite with the nitrate of silver or of thallium, 

 and the temperature of the reactions was relatively low. For 

 that reason there was little or no breaking down of the funda- 

 mental molecule. The barium and strontium salts, prepared 

 by Mr. McNeil, were obtained by fusing the mineral with 

 barium or strontium chloride, and afterwards leaching the prod- 

 uct with water, when the new compounds remained undis- 

 solved. The temperature of their formation was unavoidably 

 high, and some decomposition evidently occurred. In fact, in 

 both cases, silica and alumina were found in the leach water 

 in surprising amounts. In the preparation of strontium anal- 

 cite 36.2 per cent, of the original silica, and 23.36 per cent, of 

 the alumina were thus leached out ; and the insoluble residue 

 had the subjoined composition. The composition of the ideal 

 SrAlgSi^Ojo is given in the second column. 



Found. Calculated. 



SiOj 50.3S 53.92 



AI2O3 26.01 22.88 



SrO 23.21 23.20 



CI trace 



99.60 100.00 



The sodium of the original analcite had been completeh' replaced 

 by strontium, but the product obtained was not absolutely pure. 

 With barium analcite the results were better, as may be seen 

 in Mr. McNeil's anal3'ses of three distinct preparations. In the 

 last column I give the theoretical composition of the salt. 



Found. Found. Found. Calculated. 



SiOo 43-73 45-6i 45-22 48.54 



AljOg 20.75 20.71 21.09 20.57 



BaO 32.95 31.36 33.02 30.89 



II2O 2.02 1.78 .44 



99-45 99-46 99-77 100.00 



