60 Scientific Intelligence. [Svht, 



the triple phosphate. As the potash dissolves nothing, no urie 

 acid can be present. The crystals dissolve without effervescence 

 in muriatic acid, and are precipitated in the state of a white 

 powder by pure ammonia. These characters I consider as 

 excluding every thing but phosphate of lime. 



III. Hydrosulphurets. 



Thenard has lately published some observations on the hydro- 

 sulphurets, which deserve the attention of chemists. I shall 

 for that reason give a short account of them in this place : — 



1. When a saturated hydrosulphuret is heated along with 

 sulphur, a portion of the sulphur is dissolved, and a quantity of 

 sulphureted hydrogen gas escapes. If there be an excess of 

 alkali, the sulphur is dissolved as usual ; but little or no sul- 

 phureted hydrogen escapes. Hence we see that the hydrogureted 

 sulphurets contain less sulphureted hydrogen than the hydrosul- 

 phurets. 



2. vVhen the saturated hydrosulphurets are raised to the boil- 

 ing point, a portion of sulphureted hydrogen always makes its 

 escape. By this method the hydrosulphuret of magnesia may 

 be decomposed altogether, and hydrosulphuret of lime nearly so. 

 tiyarosulphuret of potash and soda become very alkaline. 



3. h .drosulphuret of ammonia may be obtained in crystals 

 by surrounding with ice a flagon containing a mixture of sul- 

 phureted hydrogen and ammoniacal gases. It crystallizes in 

 needles, and is white ; but becomes speedily yellow when ex- 

 posed to the air. It is very volatile, rising spontaneously to the 

 top of the phial in which it is kept. By this means it may be 

 separated from the hydrogureted sulphuret of ammonia. 



4. When ammoniacal gas and sulphur are passed together 

 through a red-hot porcelain tube, hydrogen gas and azotic gas 

 are disengaged, and a great quantity of hydrogureted sulphuret of 

 ammonia crystallized. When this substance is put into a phial, 

 pure ciystals of hydrosulphuret of ammonia gradually sublime 

 from it. 



5. The fuming liquor of Boyle smokes in oxygen gas or 

 common air; but not in azotic gas or hydrogen gas. Hence 

 the smoking must be owing to the presence of oxygen. Thenard 

 supposes that it acts by converting the liquor into hydrogureted 

 sulphuret, or into sulphite. (See Ann. de Cliim. lxxxiii. 132.) 



IV. Antimonial Acids. 



No metal has been subjected to a more persevering examina- 

 tion than antimony. But its chemical properties are so difficult 

 of investigation, that the most accurate and ingenious chemists 

 have contradicted one another in their most recent experiments. 

 Thenard found six oxides of antimony, Poust reduced them to 



