74 ' THE ATOMIC WEIGHTS. 



of course would change somewhat upon adoption of the modern ratio 

 between O and H. 



Observations upon silver acetate, like those of Liebig and Redtenbacher, 

 were also made by Marignac* The salt was prepared by dissolving 

 silver carbonate in acetic acid, and repeatedly recrystallizing. Two ex- 

 periments gave as follows: 



3-3359 g'ni- acetate gave 2.1561 Ag. 64.633 per cent. 



3-0527 " 1-9727 " 64.621 



Mean, 64.627, ± .0040 



Reduced to a vacuum, this becomes 64.609. 



In a second series, conducted with special precautions to avoid me- 

 chanical loss by spurting, Marignac found : 



24.717 gim. acetate gave 15.983 Ag. 64.665 per cent. 



21.202 " 13.709 " 64.661 " 



31-734 " 20.521 " 64.666 " 



Mean, 64.664, ± .0010 

 Or, reduced to a vacuum, 64.646 



Other experiments, comparable with the preceding series, have recently 

 been published b}^ Hardin, f who sought to redetermine the atomic 

 weight of silver. Silver acetate and silver benzoate, carefully purified, 

 were subjected to electrolysis in a platinum dish, and the percentage of 

 silver so determined. For the acetate, using vacuum weights, he gives 

 the following data, the percentage column being added by myself: 



.32470 grm. acetate gave .20987 Ag. 64.635 per cent. 



.40566 " .26223 " 64.643 " 



.52736 " .340S6 " 64.635 



.60300 " -38976 " 64.637 " 



.67235 " .43455 " 64.631 



.72452 " .46830 " 64.636 



.78232 " .50563 " 64.632 " 



.79804 " .51590 " 64.646 " 



.92101 " .59532 " 64.638 " 



1.02495 " .66250 " 64.637 " 



Mean, 64.637, ± .0011 

 Combining this series with those of the earlier investigators we have : 



Liebig and Redtenbacher 64.6065, ± .0018 



Marignac, ist series. ... 64.609, d= .0040 



Marignac, 2d " 64.646, zb .0010 



Hardin 64.637, ± .001 1 



General mean 64.636, ± .0007 



*Ann. Chem. Pharm., 59, 287. 1846. 



t Journ. Anier. Chem. f.oc, iS, 990. 1896. 



