FLUATES. 5J1 



(b.) Saturate pure liquid fluoric acid with caustic or carbonated 

 ammonia; it is at first neutral, but by evaporation becomes acid, and 

 does not crystallize. 



2. PROPERTIES. By a continued heat it evaporates, in thick white 

 vapors ; the taste is sharp, 



It is a useful fluate, being in a convenient form to be employed as 

 a test of lime, &LC. 



FLUATE OF BARYTA.* 



1. PROCESS. 



(a.) By mingling pure fluoric acid with barytic water, solid pure 

 baryta, or the native or artificial carbonate. 



(b.) To nitrate or muriate of barytes, add fluoric acid, or any 

 alkaline fluate. 



2. PROPERTIES. 



(a.) A pulverulent, fleecy precipitate, sparingly soluble in water, 

 decomposed by lime water, and by sulphuric acid. 



(b.) Soluble in an excess of fluoric acid, and in the nitric and 

 muriatic acids. 



(c.) Sometimes fluoric acid is used to distinguish between lime 

 and baryta, because the compound with the latter is more soluble 

 than with the former. 



FLUATE OF STRONTIA. 



Substituting strontia and its soluble salts, for baryta and its similar 

 salts, the facts with respect to this fluate are the same as with re- 

 spect to the preceding, and their properties are very similar. 



FLUATE OF LIME. 



Remark. As ths native fluate of lime exists in abundance, there 

 is no occasion to form it by art. 



1. PREPARATION. It may however be done, by processes per- 

 fectly analogous to those which have been stated with respect to 

 baryta and strontia, substituting lime water, with fluoric acid, or bet- 

 ter, the soluble salts of lime, with solutions of the alkaline fluates ; 

 perhaps the best is fluate of ammonia, with nitrate of lime ; the in- 

 soluble precipitate is washed and dried, 



2. PROPERTIES. 



(.) Lime and fluoric acid reciprocally take each other from every 

 thing else,\ and are therefore mutually tests ; the soluble alkaline 



* If the acid fluate of silica be poured into a solution of the muriate, or nitrate 

 of baryta, in a few minutes a multitude of small crystals are precipitated ; they are 

 very hard, insoluble in water, and in nitric and muriatic acids, and suffer no alter- 

 ation from being heated with lampblack. There can be no doubt that they are a 

 triple compound of fluoric acid, silica, and baryta. 



t Some doubt is intimated relative to fluate of magnesia. Aikins, Diet. Vql. I, p 

 441. 



