SILVER, POTASSIUM, ETC. 47 



Thorpe and Laurie's on gold. The values so obtained all confirm the 

 results already given, varying within their limits, but having probable 

 errors so high that their use would not affect the final mean. The latter 

 is obtained as follows : 



Marignac 74.077, .0030 



Stas 74.o8i, .0006 



Huntington 74-O7 1 , =b .0072 



Richards, 1st series 74.065, .0035 



" 2d " 74.067,^.0034 



General mean. ... 74.080, .00057 



In this case again, as in so many others, Stas' work alone appears at 

 the end, the remaining data having only corroborative value. 



The ratio between silver and potassium bromide was first accurately 

 determined by Marignac.* I give, with his weighings, the quantity of 

 KBr proportional to 100 parts of Ag : 



2.131 grm. Ag = 2.351 KBr. 110.324 



2.559 " 2.823 " 110.316 



2.447 2.700 " 110.339 



3.025 " 3.336 " 110.283 



3-946 4.353 " 110.314 



11.569 " 12.763 " 110.321 



20.120 " 22.191 " 110.293 



Mean, corrected for weighing in air, 110.343, , .005 



Stas,f working in essentially the same manner, as when he fixed the 

 ratio between potassium chloride and silver, obtained the following 



results : 



110.361 

 110.360 

 110.360 

 110.342 

 110.346 

 110.338 

 110.360 

 110.336 

 110.344 

 110.332 

 110.343 



110.357 

 110.334 

 "0.335 



Mean, 110.3463, .0020 



Combining this with Marignac's mean result, 110.343, .005, we get 

 a general mean of 110.3459, .0019. 



*Berzelius' Jahresbericht, 24, 72. 



f- Aronstein's translation, pp. 334-347. 



