584 Intelligence and Miscellaneous Articles. 



the oxide of donariiim were determined according to the usual 

 nietlidds.-. The following are the results of the analysis: — 



■ 'Silica 17-695 



Oxide of donarium 71'24'7 



Carbonate of lime 4'04'2 



Peroxide of iron O'SIO 



Magnesia and oxide of manganese .... 0'2I4' 



Potash witii a little soda 0-303 



Water 6-900 



100-741 

 Assuming the silica, oxide of donarium and water to form the 

 essential constituents of tiie mineral, and the carbonate of lime with 

 the other 0-825 per cent, of substances to be merely accidental impu- 

 rities, we have the following ratio : — 



Silica 18-463 



Oxide of donarium 74''338 



Water 7-199 



Oxide of donarium contains 13-072 per cent, of oxygen ; conse- 

 quently theoxygen ratio in the silicic acid, oxide of donarium and water 

 is as'l : 1 : 1^, according to which the mineral, admitting oxide of 

 donarium to have the composition R- O^, will be represented by the 

 formula Do^ O^ SiO' + 2HO, and the simplest name for the mineral 

 will be silicate of the oxide of donarium. 



The hydrate of the oxide of donarium has while moist a white 

 colour, but gradually turns yellow. It forms a bulky precipitate, 

 which is easily collected upon a filter, but is difficult to free entirely 

 from the precipitant, e.<pecially when potash or soda has been used. 

 When dried at the ordinary temperature of the air, it forms gum- 

 like masses of a yellow colour, wiiich furnish a reddish powder. In 

 this state it forms a pure hydrate of the oxide, which probably, like 

 the peroxide of iron, is capable of uniting with water in several pro- 

 portions. The water is expelled at a moderately-elevated tempera- 

 ture. The hydrate dissolves at the ordinary temperature in all acids, 

 and very quickly with the assistance of heat. No chlorine is disen- 

 gaged when hydrochloric acid is employed. 



Metallic Donarium was prepared from the oxide by heating it 

 M'ith potassium. The decomposition is very rapid, and with evolu- 

 tion of light. On treating the mass with water, the metal separates 

 as a heavy coal-black powder. When the alkaline solution is quickly 

 decanted and the powder rinsed with water, it can be kept under cold 

 water from twenty- four to thirty-six hours without any change, but 

 under hot water it gradually turns yellowish-gray, the result of 

 oxidation. The powder, when dry and rubbed in an agate mortar, 

 acquires a metallic lustre. When the powder is thrown into the 

 flame of a lamp, it burns with a reddish light into red oxide, and 

 likewise when the black powder is heated in a platinum spoon. 

 Cold and boiling hydrochloric acid have no action upon the metal. 

 Nitric acid does not act in the cold, and but very feebly on the em- 



