248 



Chloride of Aluminium and its Analysis. 



The atomic numbers deduced from the above proportions, differ 

 from those of Thomson and Berzehus only in the 4th place of figures. 



As the numbers deduced for chlorine and silver approach so near 

 to the atomic weights deduced by both Thomson and Berzelius, we 

 see that these chemists have obtained the same ratio for the com- 

 bining proportions of chlorine and silver. 



The tables e and f shew the result of the calculations c and d, 

 and they also shew the comparison of the calculated atomic weights 

 of chlorine and silver with the atomic weights of those bodies as 

 given by Thomson and Berzelius. 



Taomsmt's number. Cci-lciUated number. 



Silver, 

 Chlorine, 



Ox. =1. Ox. = 8. 



13.746171 109.96936 



4.50125^ 36.01000 



Calculated number. 



f 



Ox.= l Ox -3. Ox.= l. Ox. 8. 



Silver, 13.51607* 108.1285 13.52165t 108.17320 

 Chlorine, 4.426.50* 35.4120 , 4.42467<§> 35.39736 

 The ratios of the numbers for chlorine and silver in the above ta- 

 bles (e and f, and a) are 



1st, For Thomson's numbers. 



Berzelius' " - - 



Calculated numbers in e, 



cc cc c< f 



Numbers deduced from analysis, 



3.05555 

 3.05344 

 3.05385 

 3.05696 

 3.05476 



2d, 



3d, 



4th, 



5th, 



These ratios differ only. in the 3d place 'of decimals, and even 



there the difference is small. 



Let us how calculate the atomic weight of aluminium, using 



in the 1st proportion, Thomson's atomic weight for chlorine , 



in the 2d, the atomic weight of chlorine deduced by calculating 



from the combining proportions observed,| and Thomson's number 



for silver ; 



in the 3d, Bei'zelim' atomic weight for chlorine ; 



in the 4th,. the atomic weight of chlorine deduced by calculating 



from the combining proportions observed,J and Berzelius' number 



for silver. 



Al. CI. CI. CI. Al. 



1, a;-}-4.50000* : 4.50000: : 0.646$ : 



2, a;' +4.50 1 25^: 4.50125: :0.646t 



3, 3/4-4.42650* : 4.42650: :0.646i 

 4.y'+4.42467^ : 4.42467: :0.646J: 



Cl. 



0.5068118$ a; =1.23585 

 0.50681 18Jr'= 1.23620 

 0.5068118$ 3/= 1.21567 

 0.5068118$y'+ 1.21516 



Vide table b. 



t Vide tabled. 



Vide table a. 



§ Vide table c. 



