IQQ ^ OK THE METALS OF EARTHS. 



passedthrough When silex was employed, being in the proportion of 

 '■''^^■» about ten grains to four of potassium, no gas was evolved, 



«fxccpt the common air of the tube mingled with a little in- 

 flammable gas, not more than might be referred to the 

 moisture in the crust of alkali formed upon the potassium. 

 The potassium* was entirely des^troyed ; and glass with ex- 

 cess of alkali was formed in the lower part of the tube; when 

 this glass was powdered, it exhibited dark specks, having a 

 dull metallic character not unlike that of the protoxide of 

 iron. When the mixture was thrown into water, there was 

 only a very slight effervescence; but on the addition of 

 muriatic acid to the water, globules of gas were slowly 

 liberated, and the effect continued for nearly, an hour; so 

 that there is great reason to believe, that the silex had been 

 either entirely or partially deoxigenated, and was slowly re- 

 produced by the action of the water, assisted by the slight 

 attraction of the acid for the earth. 



When the potassium was in the quantity of six grains, 

 and the silex of four grains, a part of the result inflamed 

 spontaneously as it was taken out of the tube, though the 

 tube was quite cool, and left, as the result of its combus- 

 tion, alkali and silex. The part which did not inflame was 

 similar in character to the matter which has been just 

 described, it did not act upon water, but effervesced with 

 muriatic acid. 

 iluinanc, and Potassium, in acting upon alumlne and gluclne, produced 

 jluciRe, more hidrogen than could be ascribed to the moisture 



present in the crust of |)otash ; from which it seems probable, 

 that, even after ignition, water adheres to these earths. 



The results of the action of the potassium were pyrophoric 

 substances of a dark gray colour, which burnt, throwing off 



• The results of tliis pxperiment are opposed to the idea, that pot- 

 sssiurn is a compound of hidrogen and potash, or its basis ; for, if so, 

 it mitrht be expected, that the hidrogen would be disengaged by the 

 attraction of the alkali for silex. In my first experiments on this 

 coml»inatien, I operated in an apparatus connected with water, and I 

 found, that the potassium produced as much hidrogen, as if it had 

 heen made to act upon water j in this case the metal had rapidly de- 

 composed the' vapour of the water, which must have been constantly 

 supplied. 



brilliant 



