©ISERVATrONS ON MURIATIC ACID. 22^ 



II. 



Obfervatiom and Experiments upon Oxigenized and Hyperoxigen- 

 ized Muriatic Add ; and upon fome Combinations of the Mu~ 

 riatic Acid in its three States. By Richard Chenevix, 

 Efq. F. R. S. M. R. I. A. From the Phibfophical Tranfac- 

 tionsfor 1802. 



(Concluded from Page 185.) 

 Third Species. Hyperoxigenized Muriate of Barites, 



A HE earthy bafes feem to follow, in the order of affinities Hyperox. mur» 

 for this acid, at a great diltance from the alkalis. They are of bantcs * 

 all fuperfeded by the two juft mentioned ; and it is much more 

 difficult to accomplifh their union with the acid, than is the 

 cafe with potafh or fbda. The mod advantageous method is, 

 to pour warm water upon a large quantity of this earth, pro- 

 cured by Mr. Vauquelin's method ; and to caufe a current of 

 oxigenized muriatic acid to pafs through the liquor, kept 

 warm ; fo that the barites already diflblved being faturated, a 

 frefh portion of it may be taken up by the water, and present- 

 ed in a ftate of great divifion to the acid. This fait is foluble Soluble ; cry- 

 in about four parts of cold, and lefs of warm water. It cry- ftalllzabl e. 

 flallizes like the muriate of this earth ; and refembles it fo 

 much in folubility, that I could not feparate them effectually 

 by cryftallization repeated feveral times. At firft, indeed, I Purification of 

 defpajred of ever obtaining any of the earthy hyperoxigenized muriates^inot 

 muriates ip a Mate fufflciently pure for analylis. If we con- by diff. of fohi* 

 fider them as a genus diftinct from the alkaline hyperoxige- """TO 

 nized muriates, a leading character may be, their great re- 

 femblance to their refpective fpecies of earthy muriates. I 

 thought, however, that I might, if not by direct, at leaf! by 

 double affinity, decompofe the one without the other; and 

 phpfphate of filver occurred to me as the moft likely agent. If b y phofphate of 

 phofphate of filver be boiled with muriate of lime, of barites, double affinity * 

 &c. a double decompofition enfues ; and muriate of filver, decompofes the 

 together with phofphate of the earth, both infoluble, are pre- EJJJJ^S) 

 cipitated. To increafe the action, the phofphate of filver may perox. muriate* 

 £>e dilTolved in a weak acid, fuch as the acetous ; and, though '". r ° lutlon 

 the earthy phofphate be at firft retained in folution, it will be 



feparated 



