488 PRINCIPLES OF CHEMISTRY 



that 259-5287 grams of chlorate gave 194-44515 grams of silver 

 chloride, and after fusion 194-4435 grams. The mean result of both 

 experiments, converted into percentages, shows that 100 parts of silver 

 chlorate contain 74*9205 of silver chloride and 25-0795 parts of oxygen. 

 From this it is possible to calculate the combining weight of silver 

 chloride, because in the decomposition of silver chlorate there are 

 obtained three atoms of oxygen and one molecule of silver 

 chloride : AgC10 3 s= AgCl + 3O. Taking the weight of an atom 

 of oxygen to be 16, we find from the mean result that the equi- 

 valent weight of silver chloride is equal to 143-395. Thus if O=16, 

 AgCl= 143-395, and as the preceding experiments show that silver 

 chloride contains 32-8445 parts of chlorine per 100 parts of silver, 

 the- weight of the atom of silver 26bis must be 107*94 and that 

 of chlorine 35*45 The weight of the atom of sodium is determined 

 from the fact that 21*3633 parts of sodium chloride combine with 

 32-8445 parts of chlorine ; consequently Na=23-05. This conclusion, 

 arrived at by the analysis of silver chlorate, was verified by means 

 of the analysis of potassium chlorate by decomposing it by heat 

 and determining the weight of the potassium chloride formed, and alsd 

 by effecting the same decomposition by igniting the chlorate in a 

 stream of hydrochloric acid. The combining weight of potassium 

 chloride was thus determined, and another series of determinations 

 confirmed the relation between chlorine, potassium, and silver, in the 

 .same manner as the relation between sodium, chlorine, and silver was 

 determined above. Consequently, the combining weights of sodium, 

 chlorine, and potassium could be deduced by combining these data with 

 the analysis of silver chlorate and the synthesis of silver chloride. The 

 agreement between the results showed that the determinations made 

 by the last method were perfectly correct, and did not depend in any 

 considerable degree on the methods which were employed in the pre- 

 ceding determinations, as the combining weights of chlorine and silver 

 obtained were the same as before: There was naturally a difference, 

 but so small a one that it undoubtedly depended on the errors inciden- 

 tal to every process of weighing and experiment. The atomic weight 

 of silver was also determined by Stas by means of the synthesis of 

 silver sulphide and the analysis of silver sulphate. The combining 

 weight obtained by this method .was 107-920. The synthesis of silver 

 iodide and the analysis of silver iodate gave the figure 107-928. The 



ae tu The results given by Stas' determinations have recen.tly been recalculated and 

 certain corrections have been introduced. We give in the context the average results of 

 van der Plaat's and Thomseh's calculations, as well as in Table HE. neglecting' the 

 doubtful thousandths. 



