POTASH AND POTASSIUM. 255 



measures 116-38 cubic inches. This experiment 

 was made by plunging a given bulk of potassium 

 into water, and inferring the weight from the 

 known volume and specific gravity of this metal. 

 I have repeated it several times, employing 

 various contrivances to enable me to weigh the 

 potassium ; but I was unable to obtain better 

 results than those of the French chemists. I 

 shall therefore employ them, as they are amply 

 sufficient for the object I have in view. 



The oxygen gas, which must have united 

 with the 100 grains of potassium, must have 

 amounted to ^ = 58-19 cubic inches ; the 

 weight of which is 19*7^ grains. So that potash, 

 according to these experiments of the French 

 chemists, is composed of 



Potassium 100 or 5-121 



Oxygen 19-72 - 1 



6-121 



The weight of an atom of potash, according to 

 this experiment, is 6-121, and it is a compound 

 of one atom potassium = 5-121, and one atom 

 oxygen. Now, it is obvious, that this atomic 

 weight of potash is a little too high ; it should 

 have been 6, and not 6*121. The reason un- 

 doubtedly is, that the hydrogen gas evolved was 

 a little below the true quantity. Whoever will 

 take the trouble to repeat the experiment, will 

 be at no loss to account for this deficiency. 



