182 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 54 



STEONTIUM. 



The ratios which fix the atomic weight of strontium resemble in gen- 

 eral terms those relating to barium, only they are fewer in number and 

 represent a smaller amount of work. The early experiments of Stro- 

 meyer/ who measured the volume of CO, evolved from a known weight 

 of strontium carbonate, are hardly available for the present discussion. 

 So also we may exclude the determination by Salvetat," who neglected 

 to publish sufficient details. 



Taking the ratio between strontium chloride and silver first in order, 

 we have series of figures by Pelouze, Dumas, Marignac and Eichards. 

 Pelouze ^ employed the volumetric method to be described under barium, 

 and in two experiments obtained the subjoined results. In another col- 

 umn I append the ratio between SrCL and 100 parts of silver : 



1.480 grm. SrCL=: 2.014 grra. Ag. 73.486 



2.210 " 3.008 " 73.471 



Mean, 73.4781 ± .0050 



Hence Sr = 87.614. 



Dumas,'' by the same general method, made sets of experiments with 

 three samples of chloride which had previously been fused in a current 

 of dry hydrochloric acid. His results, expressed in the usual way, are 



1 Schweigg. Journ. , 19, 228. 1816. 



^Coinpt. Rend., 17, 318. 1843. 



'Oompt. Rend., 20, 1047. 1845. 



* Ann. Chim. Phys. (3), 55, 29. 1859. Ann. Chem. Pliarni., 113, 34. 



