the Decomposition of the Earths, &c. 211 



Formed with equal rapidity. In this process of deoxida- 

 tion, when the battery was in powerful action, a black matter 

 formed in the cavity, which there is every reason to believe 

 was carbonaceous matter from the decomposition of the car- 

 bonic acid of the carbonate *. 



The strong attraction of potassium, sodium, and the me- 

 tals of the alkaline earths for oxyen, induced me to examine 

 whether their deoxidating powers could not be made to 

 produce the effect of the amalgamation of ammonia, inde- 

 pendently of the agency of electricity ', and the result was 

 very satisfactory. 



When mercury, united to a small quantity of potassium, 

 sodium, barium, or calcium, was made to act upon moisten- 

 ed muriate of ammonia, the amalgam rapidly increased to six 

 or seven times its volume, and the compound seemed to con- 

 tain much more ammoniacal basis than that procured by elec- 

 trical powers. 



As in these cases, however, a portion of the metal used 

 for the deoxidation always remained in union in the com- 

 pound ; in describing the properties of the amalgam from 

 ammonia, I shall speak only of that procured by electrical 

 means. 



The amaloam from ammonia, when formed at the tem- 

 perature of 70° or SO, is a soft solid, of the consistence of 

 butter ; at the freezing temperature it becomes firmer, and a 

 crystallized mass, in which small facets appear, but having 

 no perfectly defined form f. Its specific gravity is below 3, 

 water being one. 



When exposed to air it soon becomes covered with a white 

 crust, which proves to be carbonate of ammonia. 



When thrown into water it produces a quantity of hy- 

 drogen, equal to about half its bulk, and in consequence 



* The black matter which separates at the negative surface in the electri- 

 tal experiments on the decomposition of potash or soda, and which some' 

 experimenters have found it difficult to account for, is, I find, carbonaceous, 

 and dependent upon the presence of carbonic acid in the alkali. 



| From the facet I suspect the form to be cubical. The amalgam of po- 

 tassium crystallizes in cubes as beautiful, and in some cases as large, as tho?e 

 uf bismvth, 



O 2 of 



