WRITINGS OF JAMES SMITHSON. 55 



of magnesia, clay, copper, iron, and zinc, either had no 

 effects, or extremely slight ones. 



k. Solution of sulphate of silver produced a white curd, 

 like precipitate. 9.35 grains of this salt (the weight of the 

 insoluble matter being deducted) afforded 1.05 grains of 

 slightly melted muriate, or chloride, of silver. This pre- 

 cipitate was equally produced after the salt had been made 

 strongly red hot, so that it was not owing to a portion of 

 sal ammoniac. 



I Tartaric acid, and muriate of platinum, occasioned the 

 precipitates in its solution which indicate potash. 



m. Nitrate of lime did not form any immediate precipi- 

 tate in a dilute solution of it ; but. in a short time, numerous 

 minute prismatic crystals of hydrate of sulphate of lime 

 were generated. 



n. Nitrate of barytes poured into a solution containing 

 9.8 grains of this salt afforded a precipitate, which after be- 

 ing ignited weighed 12.3 grains. The filtered solution 

 crystallized entirely into nitrate of potash mixed with a 

 few rhomboides of nitrate of soda. 



o. Some of this salt finely pulverized was treated with 

 alcohol. This alcohol on exhaling left a number of minute 

 cubic crystals, which proved, by the test of nitric acid, to 

 be muriate of soda. Prussiate of soda-and-iron caused a 

 red precipitate of prussiate of copper in this alcoholic solu- 

 tion. 



p. The solution of this salt afforded, by crystallization, 

 sulphate of potash in its usual forms, and some prismatic 

 crystals of hydrate of sulphate of soda. 



q. To discover what had occasioned the precipitate with 

 galls, (i) since copper has not this quality, a portion of this 

 salt, which had been recovered by evaporation from a fil- 

 tered solution of it, was made red hot in a platina crucible. 

 On extraction of the saline part by water, a very small 

 quantity of a black powder was obtained. Ammonia dis- 

 solved only part of it, which was copper. The rest being 



