414 Intelligence and Miscellaneous Articles. 



run through it, must be dried without washing, in the funnel ; the 

 oxide of tin contracts in drying, is partly peroxidized, and eventually 

 loses its property if passing through the filter with water ; the wash- 

 ings are then to be added to the first liquor, and the whole, acidulated 

 by nitric acid, is precipitated by nitrate of silver. It is very import- 

 ant to boil the matter for some time with the carbonate of soda; 

 without this precaution, the decomposition would be imperfect, and 

 there would be a loss of chlorine. 



To determine the tin, the filter containing the oxides of mercury 

 and tin is to be dried ; it is then to be treated with pure nitric acid, 

 in a porcelain crucible, and this is then to be heated til] the filter is 

 perfectly burnt. The crucible is then to be weighed, and the tin is 

 determined by the weight of the stannic acid produced. 

 One hundred parts yielded 



Mercury 60 '31 



Tin 17-68 



Chlorine 21*09 



100-08 

 The results correspond to the following constitution : 

 Mercury. . 2 atoms . . 2531-65 or 60-97 



Tin 1 atom ., 735-29 .. 17-71 



Chlorine. . 4 atoms . . 885-30 . . 20-31 



4152-24 100- 

 Journal de Pharmacie, September, 1839. 

 [The equivalent of mercury being taken as 202, that of tin 58, 

 and of chlorine 36, it will be seen that this compound consists of 

 One equivalent of protochloride of mercury. . . . 238 

 One equivalent of protochloride of tin 94 



332. R. P.] 



ANHYDROUS PROTOCHLORIDE OF TIN. 

 M. Capitaine gives the following as a simple and very ceconomical 

 method of preparing anhydrous protochloride of tin : Heat the mu- 

 riate of tin of commerce in a large Hessian crucible ; it is not pos- 

 sible to perform the operation in a retort, as some authors advise, 

 for the salt swells and passes over into the receiver without under- 

 going any alteration ; when moderately heated in the crucible it 

 fuses, swells and yields the vapour of water and of hydrochloric acid ; 

 soon after this it undergoes igneous fusion, and when in quiet fusion 

 it is to be poured into a smaller crucible. On cooling it becomes a 

 brown mass, which is to be reduced to coarse powder and distilled in 

 a coated glass retort. The first product is perfectly pure, the latter 

 contains a little iron, which is to be separated by redistillation. 

 The properties of this substance are that it is compact, nearly of a pure 

 white colour, brittle, and has a vitreous fracture ; when heated it 

 fuses at about 482° Fahr., boils, and volatilizes at a little below a red 

 heat. It possesses a property which must always prevent the den- 

 ity of its vapour from being ascertained, which is that it is never 

 ompletely volatilized without vuidergoing partial decomposition, the 



