1819.] Prof. Fuchs on Lasionite and Wavdlite. 277 



analysis in the following way : I dissolved 25 gr. in caustic 

 potash, and added a small additional quantity of potash to the 

 solution, poured into it a solution of muriate of lime prepared 

 with 25 gr. of carbonate of lime, and allowed the mixture to 

 digest for a short time. The whole was then thrown upon the 

 filter, and the alumina separated from the liquid which passed 

 through by means of sal-ammoniac. It weighed, after being 

 dried in a red heat, 9-14 £r. did not tins;e the tiame of the blow- 

 pipe, and with sulphuric acid and potash it formed alum. 



The precipitate obtained by means of the muriate of lime, 

 which consisted of phosphate of lime with excess of base, 

 dissolved with slight effervescence in muriatic acid. From this 

 solution the phosphate of lime was precipitated by means of 

 caustic ammonia, separated on the filter, well washed with hot 

 water, dried, and heated to redness. It weighed 19*2 gr. had 

 a gummy-like appearance, was infusible, dissolved without effer- 

 vescence in nitric acid, and acetate of lead threw down a 

 copious precipitate from the solution, which, when exposed to 

 the flame of the blow- pipe on charcoal, melted into a shining 

 polyhedral button. After these trials, I held it superfluous to 

 seek any further evidence of the existence of phosphoric acid in 

 it; but it was still uncertain how much of this acid, phosphate of 

 lime contains. To ascertain this, I dissolved 50 gr. of Iceland 

 spar in muriatic acid, mixed the solution (after driving off the 

 excess of acid by evaporation) with some caustic ammonia, and 

 precipitated the phosphate of lime by means of phosphate of am- 

 monia.* It possessed exactly the qualities of the phosphate of 

 lime obtained in the analysis of the lasionite. After being heated 

 to redness, it weighed 51*52 gr. If we allow calcareous spar to 

 contain 56*4 per cent, of lime, it follows that our phosphate of 

 lime, which possesses the characters of a neutral salt, is com- 

 posed of 



Phosphoric acid 45*26 



Lime 54-74 



100-00 

 This very nearly corresponds with Klaproth's analysis of 

 apatite. Hence it follows that 19*2 gr. contain 8*68 gr. of 

 phosphoric acid, and the result of the analysis of 25 gr. of lasio- 

 nite is : 



Alumina 9-14 



Phosphoric acid 8-68 



Water 7-00 



24-82 



• When the two neutral solutions are mixed together, we obtain a slimy, pearly 

 powder, which acts as a weak acid, melts easily before the blow-pipe, and gives 

 the tlame a hluish-sreen colour. This salt, which contains much more phosphoric 

 acid than that obtained in the way described in the text, is a biphosphate of lime. 

 We have here an example of Richtcr's well-known law. 



