404 F.xperi-ments uilh Hydrochloric Acid 7ipon Tin, ^c. 



On recallinq; to inlncl the process which is used to extract by 

 means of nitric acid the silver contained in gold, and the neces- 

 »;itv tliere is in that case of employing three parts of silver to 

 one of gold — a process commonly known by the name of 

 qiiartaliov, — it occurred to me that tin might be to antimony as 

 silver is to gold, and that the proportion of tin neccssiiry to the 

 qiiartalion of antimony ought to he much greater than what 

 I had used in the ]U'eceding experiment;;, — that this only re- 

 quired to he sought after to be ascertained. I accordingly made 

 the following experiment : 



Third Experiment. 1 weighed with great care, in a balance 

 capable of intiicating the very nicest proportions, ten parts of an- 

 timonv and 90 parts of tin, being as nine to one. I envelojjcd 

 the whole in a piece of paper, placed it in the bottom of a small 

 experimenting crucible, covered it with a layer of fine powder 

 of charcoal, in order to prevent oxidation, and subjected it to 

 the heat of an essay furnace for ten minutes. I then withdrew the 

 crucible from the fire, and allowed it to cool. On examining it 

 I found a small drossy mass, which I first brushed carefully, then 

 flatteued,and arfterwards cut into a number of pieces. Iwrapped up 

 these anew in paper, and subjected them to the heat of the stove 

 in the same manner as before. The mixture being again cooled 

 and well brushed, was without being flattened fused a third time, 

 and only a very small slip of paper interposed between it and the 

 charcoal. The residue which I now obtained consisted of a small 

 compact knob, of metallic brilliancy, and exactly 100 parts in 

 weight. I flattened this as thin as I could, and cut it with 

 scissars into small fragments, which 1 put into a phial and after- 

 wards saturated with hydrochloric acid. Having boiled the 

 whole for two hoxirs, I allowed it to cool, and then collected upon 

 a filter the portion not dissolved. I found it to be of the weight 

 of twelve parts in place of ten. 



Fourth Experiment. I joined ^ith the same care as in the 

 preceding experiment, five parts of antimony to 100 of tin, behig 

 as 1 to 20. The knob obtained as before, being flattened as 

 thin as possible, cut into pieces, and these put into glass ; I sa- 

 turated them with hydrochloric acid. The action was quick, 

 and at the end of a (juarter of an hour the dissolution appeared 

 almost complete. The antimony abstracted floated in the li- 

 quor : I made it itill boil for two hours longer ; and on then 

 collecting the residue on a filter, I found just five parts of anti- 

 mony — being the precise quantity which I had put into the mix- 

 ture. 



On repeating this experiment, I obtained exactly the same 

 result. 



I made 



