50 THE ATOMIC WEIGHTS. 



From the weight of silver iodide actually collected we get as follows. 

 For experiment number three in the above column there is no equivalent 



here: 



117.529 

 117.531 

 117-539 

 117-538 

 ii7-53 



Mean, H7-5334, d= .0014 



Now, combining these several sets of results, we have the following 

 general mean : 



Marignac H7-5335, .3 6 



Stas, ist series ii7-53 2 5, - OO2 4 



" 2d " "7-5373, .ooi5 



" 3d " II7-5334, =t .0014 



General mean "7-5345, .0009 



One other comparatively unimportant iodine ratio remains for us to 

 notice. Silver iodide, heated in a stream of chlorine, becomes converted 

 into chloride ; and the ratio between these two salts has been thus deter- 

 mined by Berzelius and by Dumas. 



From Berzelius * we have the following data. In the third column I 

 give the ratio between Agl and 100 parts of AgCl : 



5.000 grm. Agl gave 3.062 AgCl. 163.292 



12.212 " 7-4755 " 163.360 



Mean, 163.326, .023 



Dumas' f results were as follows: 



3.520 grm. Agl gave 2.149 AgCl. 163. 793 



7.011 " 4.281 " 163.770 



Mean, 163.782, .008 



General mean from the combination of both series, 163.733, .0076. 



For sodium there are but four ratios of any value for present purposes. 



The early work of Berzelius we may disregard entirely, and confine 

 ourselves to the consideration of the results obtained by" Penny, Pelouze, 

 Dumas, and Stas, together with a single ratio measured incidentally by 

 Earn say and Aston. 



The percentage of oxygen in sodium chlorate has been determined 

 only by PennyJ, who used the same method which he applied to the 

 potassium salt. Four experiments gave the following results : 



* Ann. Chim. Phys. (2), 40, 430. 1829. 

 t Ann. Chem. Pharm., 113, 28. 1860. 

 J Phil. Transactions, 1839, p. 25. 



