•ir THE ALKAMNE METALLOIDS. ggl 



iction both on the porcelain and the silver is considerably but less than o» 

 Jess than that on the platina, and I employed them there, ^ **^"^* 

 fore ia the following experiments. 



Seven grains of potassium were bnrnt on a silver basin. Experimertt 

 During the combustion a portion was dissipated in a dense bunied'onsuT 

 w^itc smoke, and the product did not exceed 7 grains ; it ver. 

 was of a grayish colour, and fusible, remaining soft and 

 nearly liquid, at a low red heat. Five grains of it were 

 weighed while warm, and were dissolved in water. The 

 solution was nearly transparent, depositing only a few 

 floGCuli. It was neutralized by an acid, composed of one 

 part of nitric acid, by weighty and twenty parts oi ^water, 

 and of which 5 grains of ignited potash neutralized 139 

 grains *. The quantity required for neutralization, after 

 separating the insoluble matter, and allowing as accurately 

 as possible for its weight, was equivalent to 144 grains to 

 5 grains of the product free from this matter, and similar 

 results, with differences of not more than 2 or 3 grains, 

 were obtained on several repetitions of the experiment. 



Seven grains of potassium were burnt on a cup of Chinese Potassium 

 porcelain. The product was lighter in colour than in the ^^[^"^ °* 

 preceding experiments, being of a yellowish gray, nearly 

 ■white. Five grains of it were weighed while warm, and dis- 

 sofved in water. A flocculent gelatinouslike precipitate 

 subsided, which, as it was found to be dissolved in a pre- 

 ceding experiment by a very weak acid, was removed before 

 neutralization, dried, and weighed. The solution required 

 for neutralization, of the diluted nitric acid, a quantity equal 

 to 141 grains to 5 grains of the product free from this in- 

 soluble matter. 



These experiments then, in common with those I have The product 

 formerly stated, appear to establish the conclusion, that J'j^J j|,"^^mmr« 

 the potash produced by the combustion of potassium is fused poush. 

 very little superior in the power of neutralizing an acid, to 

 the common fused potash. It is with much caution that I 

 have admitted this conclusion, as the opposite result has 

 been supposed to be established, on the authority of some 



* The acid which I used in my former experiments was com- 

 posed of one part of nitric acid by measure with 20 parts of water. 



eminent 



