426 



PROCEEDINGS OP THE AMERICAN ACADEMY. 



The platinum-plMted brass weights were twice carefully staodardized 

 to hundredths of a milligram, and the two sets of corrections agreed to 

 within two hundredths of a milligram in every case. Two short-armed 

 Troemner balances, sensitive to a fiftieth of a milligram with a load of 

 fi.fty grams, were used in the work. All weighings were made by sub- 

 stitution. In the case of the Gooch crucible a platinum tare, and in 

 the case of the porcelain crucibles, porcelain tares were used. 



In the following table are given the results of all the syntheses which 

 were completed without accident. The atomic weight of silver is as- 

 sumed to be 107.930 in the calculations. 



The results tabulated in the preliminary series were undoubtedly less 

 accurate than those of the final series, since it was in these analyses that 

 experience in handling silver iodide was gained. Hence these analyses aie 

 collected by themselves. In the final series the i-ejection of Analysis 12 

 seems justifiable, since two other analyses made with the same material 



* The values for the density of silver iodide found ]>y other e.xiieriiiicnters are 

 as follows : 



Boullay, Ann. de Chira. et de Pliys., (2) 43, 266 (1830) .... 5.614 



Karsten, Jour, fur Chem. und Phys., 65, 417 (1832) 5.026 



Filiiol, Ann. de Chim, et de Phys., (3) 21, 417 (1847) .... 5.500 



Scliiif, Ann. der Ciiem. und Pliarm., 108, 21 (1858) 6.35 



II. St. Chiir Devillo, Comptes llendus, 64, 325 (1867) .... 5.687 at 0" 

 Sciiroeder, Ann. der Ciiem. uiid Pharni , 192, 295 (1878) . . 5.r..')0 to 5.718 



