220 Literary and Philosophical Society. 



' " Is it possible by Beguin's spirit of sulphur (a sulphide 

 of ammonium chiefly) to decompose the luna cornua, or to 

 separate the muriatic acid entirely without loss ? 



* " To settle this question we require only the following 

 experiments. Muriatic acid has a smaller degree cf affinity 

 with silver than with the volatile salt. Sulphur, on the 

 other hand, unites with silver in preference to the volatile 

 salt. The silver is not separated from the muriatic acid 

 by the volatile salt on account of accidental circumstances, 

 but this separation follows the moment any other body 

 unites with the silver, if it has not the property of dissolving 

 the silver. But sulphur is just such a body, and is there- 

 fore fitted for the purpose. If, then, the spirit of sulphur 

 of Begtiin is poured on finely powdered luna cornua, it is 

 easily seen that the muriatic acid in the luna cornua must 

 unite with the volatile salt in the spirit of sulphur, and 

 the sulphur will unite with the silver. The new products 

 that are formed by this separation can consequently be no- 

 thing more than common sal-ammoniac and sulphuretted 

 silver." 



* Page 452. *' Another similar question arises by which 

 the proportions of the mixture must be considered. How 

 much cinnabar must be mixed with the luna cornua so as 

 completely to separate the silver ? 



' " The possibility of this decomposition may be shown 

 in the same way as in the first case. If no particular 

 experiment is made, it depends on the comparison only 

 of the following propositions. Half an ounce of fine silver 

 takes up 35-^ grains of sulphur. We may then calculate 

 that for 180-f^g- grains of fine silver, 26 J grains of sulphur 

 are required. We know besides that cinnabar contains 

 sulphur in the proportion of 65 to 240 of quicksilver, or 65 



