NITROGEN. 



41 



But neither of these series can for a moment compare 

 with that of Stas.* He used from 12.5 to 80 grammes of 

 silver in each experiment, reduced his weighings to a vac- 

 uum standard, and adopted a great variety of precautions 

 to ensure accuracy. He found for every 100 parts of silver 

 the following quantities of NH^Cl : 



49.600 



599 



597 



598 



597 



593 



597 



5974 



602 



597 

 598 

 592 



Mean, 49-5973. ± -oooS 



Now, combining these three series, we get : 



Pelouze 49-5365, ± -013 



Marignac 49.523, =t -0055 



Stas 49-5973> ± -oooS 



General mean 49-597, ±.0005 



The quantity of silver nitrate which can be formed from 

 a known weight of metallic silver has been determined by 

 Penny, by Marignac, and by Stas. Pennyf dissolved silver 

 in nitric acid in a flask, evaporated to dryness without 

 transfer, and weighed. One hundred parts of silver thus 

 gave of nitrate : 



157-430 



157-437 



157-458 



157.440 



157-430 

 157-455 



Mean, 157.4417, i .0033 



*Aronstein's Translation, pp. 56-58. 

 t Phil. Trans., 1839. 



