THE ANALYSIS OF POTASSIC CHLORIDE. 



THE RATIO OF POTASSIC CHLORIDE TO SILVER. 



In this series of experiments, weights of the purest silver equivalent to 

 entirely new portions of fused potassic chloride, as calculated from the pre- 

 ceding table, were dissolved in nitric acid, and the two equivalent solutions 

 were mixed. Great care was used. The presence of an excess of silver 

 or of chlorine was then determined with the nephelometer, exactly accord- 

 ing to the details of manipulation adopted by Richards and Wells, whose 

 accounts should be consulted for particulars. The table below contains 

 the final results ; the preliminary practice experiments are omitted for the 

 same reason as before. 



Final Scries of Determinations of the Ratio Ag: KCl. 



In this case the "probable" error is even somewhat less than before, 

 being under 0.0004. 



DISCUSSION OF FINAL RESULTS. 



Thus two results have been obtained, giving for the atomic weight of 

 potassium the value 39.113 by reference to argentic chloride, and the 

 value 39.114 by reference to pure metallic silver. The close agreement 

 of these results is an important evidence of their verity, and a striking 

 confirmation of the new atomic weight of chlorine found by Richards and 

 Wells. The atomic weight of chlorine is very simply calculated from the 

 results of the two series above as follows: Cl = = (69.1073/52.0118- 

 1.00000) 107.93 -- 35.47.5 --very near the most likely value, 35,473. 



Such difference as exists is probably due to the slight remaining trace 

 of occlusion of foreign salts by the argentic chloride. In the present case 

 this source of error was eliminated more successfully than ever before, 

 hence the agreement between the two values of the atomic weight of 

 potassium was closer than usual. 



