METALS AND THEIR COMPOUNDS. 95

METALS AND THEIR COMPOUNDS.

Alumen EXSICCATÜM.

Take any convenient quantity of alum ; fuseit over the fire in avessel of iron or earthen-Ware ; continue the heat tili cbullition ccasesand vapour is no longcr discharged; and tlienreduce it to powder.

ANTIMONII OXIDUM.

Take of Sulphuret of Antimony in fine pow-der, four outices ;Muriatic acid (commercial,) one

pint;Water, five pints.Dissolve the sulphuret in the acid with theaid of a gentle heat; boil för half an hour ;filter ; pour the fluid into the water ; collectthe precipitate on a calico filter ; wash itwell with cold water, then with a weak Solu-tion of carbonate of soda, and again with coldwater tili the water ccases to affect reddcnedlitmus paper. Dry the powder over the va-pour bath.

Pulvis antimonialis.

Take of Sulphuret of Antimony, in coarsepowder;Hartshorn shavings, equal wcights ;Mix them, put thcm into a red-hot iron pot,