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 

 117-530 



Mean, 117.5334, d= .0014 



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

 general mean : 



Maiignac ii7-5335, ± -OOj^ 



Stas, 1st series 1 17-5325, ± -0024 



" 2d " "7-5373, ± •0015 



" 3d " 117-5334, ± -OOH 



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 " T63.360 



Mean, 163.326, d: .023 



Dumas' t results were as follows: 



3.520 grm. Agl gave 2.149 AgCl. 163.793 



7. on " 4.281 " 163.770 



Mean, 163.782, =b .ooS 

 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 ma}'' 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 Penny|, 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. i860. 

 I Phil. Transactions, 1S39, p. 25. 



