386 Intelligence and Miscellaneous Articles. 



goodness of the solution to be owing. The experiments upon which 

 this opinion is founded are the following. 



1st. The solution of protomuriate of tin, as neutral as possible 

 when mixed with a solution of gold, gives a maroon, brown, blue, 

 green or metallic precipitate, according to its concentration and pro- 

 portion, but the colour is never purple. 



2nd. Pure permuriate of tin, whether acid or not, produces no 

 change in the same solution of gold, whatever be the proportions em- 

 ployed. 



3rd. A mixture of one part of protomuriate, nearly neutral, and 

 two parts of permuriate of tin, with one part of muriate of gold, in- 

 stantly occasions a fine purple colour. Founded on these facts, M. 

 Buisson gives the following process for obtaining the purple powder : 



4th. Dissolve about 15 grains of granulated tin in muriatic acid, 

 either with or without heat, taking care that the solution is neutral. 



5th. Prepare a solution of permuriate of tin by dissolving about 30 

 grains of tin in a sufficient quantity of aqua regia, composed of three 

 parts of nitric acid and one part of muriatic acid ; taking care that the 

 solution is neutral, and free from protomuriate, which is determined 

 by its giving no precipitate with a solution of gold. 



6th. To prepare the solution of gold, dissolve about 108 grains of 

 gold in aqua regia, composed of one part of nitric acid and six parts 

 of muriatic acid ; the solution should be nearly or quite neutral. 



Dilute the solution of gold, so that a pint of it contains about 15 

 grains of the metal. Pour in the permuriate of tin and mix them 

 well, then add drop by drop the protomuriate, till the required tint 

 is produced, remembering that the protomuriate causes a brown, 

 and the permuriate a violet colour, and intermediate proportions give 

 a red. Wash the precipitate as quickly as possible, that no action 

 may take place between the salts of tin and the precipitate, which 

 alters its colour. 



The purple powder of a fine tint yielded by analysis : 



Metallic gold ". 28*5 



Peroxide of tin 65'9 



Chlorine 5 2 



996 

 Loss 4 



100-0 

 Journal de Pharmacie, October, 1830. 



ANALYSIS OF VEGETABLE PRODUCTS. 



The following are the results of analysis by MM. Henry, jun. and 

 A. Plisson : 



Sugar. — Carbon 44*104 



Hydrogen 6*136 



Oxygen 49760 



100-000 



Kink 



