328 Mr. Maddrell on the Metaphosphates. 



carbonate of barytes in diluted phosphoric acid, then evapo- 

 rating and heating it up to 600° F. ; it is insoluble in -water, 

 hydrochloric acid and aqua regia, but decomposed by con- 

 centrated sulphuric acid. This salt Avas heated with concen- 

 trated sulphuric acid, digested in water, and filtered, and the 

 PO5 estimated from the loss. 



Found. Atom. Reckoned. 

 Per cent. 



1-236 (rrm. substance gave -974 BaO, S03 = -639 BaO = 51-70 BaO =51-746 



PO5 as loss = 48-30 PO5 =48-254 

 100-00 100-000 



Formula, BaO, PO5. 



Metupliospliate of Strontian. — This compound was obtained 

 by decomposing carbonate of strontian in diluted phosphoric 

 acid, evaporating and heating as before; it is insoluble in 

 water, hydrochloric acid and aqua regia, but decomposed by 

 concentrated sulphuric acid. 



This salt was heated with concentrated sidpluiric acid, and 

 then the mass digested in water, mixed with alcohol, and fil- 

 tered. The POr was estimated from the loss. 



Found. Atom. Reckoned. 

 Per cent. 



1-014 grm. substance gave -755 SrO, S03=-425 SrO = 41-913 SrO =42-043 



PO; as loss = 58-08 7 POj =57-957 

 100-000 100-000 



Formula, SrO, PO5. 



Metap)hQsphate of Lime. — This compound was obtained in 

 a similar manner to the salts of barytes and strontian. It is 

 a white, anhydrous powder, insoluble in water and diluted 

 acids, but decomposed by concentrated sulphuric acid. The 

 analysis of this salt was made the same as the salt of stron- 

 tian. 



Found. Atom. Reckoned. 



•806 arm. substance gave -550 CaO, S03 = -2284 CaO = 28-337 CaO =28-52 



PO5 as loss = 71-663 PO5 =71-48 



100-000 100-00 



Formula, CaO, PO5. 



Metaphosphate of Magnesia was obtained by dissolving car- 

 bonate of magnesia in an excess of diluted phosphoric acid, 

 evaporating, and heating as before; it may also be obtained 

 by preparing phosphoric acid from bone-ash, according to the 

 above-mentioned process. It is a white, anhydrous com- 

 pound, insoluble in water and diluted acids, but soluble in 

 concentrated sulphuric acid. This compound was dissolved in 

 pure concentrated sulphuric acid, diluted with water, and 

 precipitated by an excess of ammonia. The filtered solution 

 containing the remainder of the phosphoric acid was preci- 



