VOL. LXXXII.] PHILOSOPHICAL TRANSACTIONS. 133 



Exper. 2. The dry residuum obtained as before was rubbed with a little alcohol, 

 and a sufficiency of this spirit having been added, the whole was placed in a gentle 

 warmth, and often stirred with a glass tube : after a few days the fluid was de- 

 canted, and what remained indissoluble having been edulcorated with alcohol, 

 and carefully collected and dried in a moderate warmth, was found to weigh 1392 

 grs.; so that 168 grs. had been taken up by the alcohol. The spirituous solution 

 was gently evaporated, when 180 grs. of a yellowish easily deliquescent salt re- 

 mained, having a bitter and acrid taste. By adding to this 1 oz. of the strongest 

 alcohol, all the deliquescent salts were dissolved, leaving 40 grs. of a saline sub- 

 stance ; which having been again dissolved in distilled water and crystallized, was 

 found to be common salt. The solution of the deliquescent salts having been 

 mixed with 20 drops of pure vitriolic acid, some selenite appeared ; the whole was 

 now evaporated to dryness, and having been mixed with 4- of its weight of pure 

 vitriolic acid, it was exposed to a considerable heat. The vapours thus expelled 

 were those of the muriatic acid. When these had ceased, and the mass was cold, 

 it was again dissolved in distilled water, when a black, flaky substance was sepa- 

 rated, which being carefully collected on filtering paper, and dried, weighed 6 grs. ; 

 this was resinous matter. The solution was now placed on the fire, in order to 

 evaporation, during which 12 grs. of selenite were separated; the remainder 

 afforded vitriolated magnesia, leaving some drops of a yellowish fluid, from which^ 

 by the addition of caustic volatile alkali, a very small quantity of calx of iron was 

 precipitated, which when dry weighed about -l of a grain. 



It appears, from the above experiments, that the spirituous solution held of, 

 muriated soda 40 grains ; muriated magnesia 128 grains; muriated calcareous 

 earth 6 grains ; resinous matter 6 grains ; calx of iron -f grain. 



Exper. 3. The residuum of the 2d experiment, which was not soluble in 

 alcohol, was digested with distilled water, and often stirred. The water took up 

 1204 grs. This solution was filtered, the residuum often edulcorated and dried ; 

 this weighed 188 grs. The solution was evaporated in a gentle warmth to -f, and 

 being then set in a cold place, 1 2 grs. of selenite were separated. Having further 

 evaporated the remaining solution, Mr. S. now mixed it with double its weight of 

 alcohol, and after having again heated this mixture, he let it cool gradually ; 

 thus all the vitriolic salts were separated. He again dissolved this saline mass in 

 distilled water, and after gentle evaporation obtained crystals, weighing altogether 

 1200 grs. and consisting of vitriolated tartar, and vitriolated soda : from the re- 

 maining ley he obtained, on further evaporation, 10 grs. more of common salt. 

 There were no traces of an uncombined alkali, which must otherwise have now 

 shown itself. The 1200 grs. of mixed salts, which had crystallized first, were 

 again dissolved in water, and this solution made to boil ; a hot solution of mineral 

 alkali was now mixed with it, and the magnesia thus separated weighed, when 



VOL. XVII. X 



