a< 



Chloride of Aluminium and its Analysis. 247 



0.6460000 Chloride of aluminium. 

 2.0549731 Chloride of silver. 

 1.54S161 Silver. 

 0.506811 Chlorine. 

 0.297500 Alumina. 

 ^0.139188 Aluminium. 

 Before we can determine whether the chloride analyzed be a chlo- 

 ride or sesqui-chloride of aluminium, it will be necessary to adopt 

 some atomic numbers, and compare the combining proportions ob- 

 tained in the analysis with the number adopted. 



The numbers in common use are those of Thomson and Berzelius. 

 Atomic weights according to 



Tkomson. Berzcliii!!. 



, "■ ^ . "- s 



Oxvgen. Oxvgen. Oxygen. Oxygen. 



'18 1 8 



rSilver, *13.75 110 *13.51607 108.1285 



, J Chlorine, *4.50 36 *4.42650 35.4120 



^1 Aluminium, \\Slh 10 11.71166 13.6932 



t Alumina, <^2.25. 18 **6.42332 **5 1.471 



The atomic weight of chlorine in Berzelius' number of the above 

 table (b) is double the number that he assigns it, for he thinks the 

 combination of silver and chlorine a bichloride. 



Let us now calculate the atomic weight of chlorine, using the 

 combining proportions of silver and chlorine deduced from the pre- 

 ceding analysis, and Thomson's and Berzelius' number for silver. 

 Sih^er. Clilorine. S. CI. CI. 



5 1.54816111 : 0.50631 1 II : :13.75!I : x and a:=4.50125 

 ^\ 1.54816111 : 0.50681111 :: 13.5160711 : x' and a;' = 4-42467 

 The numbers deduced for the atomic weight of chlorine differ 

 from those of both Thomson and Berzelius only in the third place 

 of decimals. Let us now calculate the atomic weight of silver upon 

 the same data, only using Thomson's and Berzelius' numbers for 

 chlorine. 



Chlorine. Silver. CI. S. S. 



,50.50681111 : 1.54816111 ::4.51I \x and a;=13.74617 

 ^ 0.50681111 : 1. 548161 II :: 4.426511 : x' and a;' = 13.52165 



♦ Thomson's Inorganic Chemi.stry, Lond. 1831, Vol. I. p. 633. 

 t Idem, Vol.1, p. 454, and Thom.son's First Principles, Vol. I. p. 318. 

 t Annales de Chimieetde Physique, Tome LII. p. 132. 

 § Thomson's Inorganic Chemistry, Vol. 1. p. 454, and Thomson's First Princi- 

 ciples. Vol I. p. 318. 



II Vide table a. ^ Vide table b. 



♦♦ Berzelius' Traill de Chimie, Tome v. p. 9,lable synoptique. 



