Chemical Science. 409 



36. ON THE COMBINATION OP CHLORIDE OP GOLD WITH THE 

 CHLORIDE OF POTASSIUM AND SODIUM. (Berzelius.) 



The analysis of the oxide of gold and the other compounds of this 

 metal has led to such various results, as to render it impossible to 

 form any certain conclusion with regard to the proportion of their 

 elements. The recent investigations of Berzelius on the subject are 

 accordingly of much interest, especially as they, in some degree, 

 tend to confirm his views on the atomic weight of gold. We give 

 an extract from his paper in the Kongl. Vetensk. Handl. of 1829. 



It is known that Pelletier was led, by the results of his inquiry 

 into the composition of the iodide of gold, to consider the atomic 

 weight of gold different from that which had been adopted by Ber- 

 zelius ; but that the views of the Swedish philosopher were strength- 

 ened by the subsequent researches of Javal, and particularly by his 

 analysis of the compound of the chlorides of gold and of potassium, 

 which he found to consist of 24.26 of chloride of potassium, 68.64 

 of chloride of gold, and 7.10 of water, the gold being accordingly 

 united to twice as much chlorine as the potassium. Figuier, who 

 soon after Javal examined the same subject, discovered the com- 

 pound of the chloride of gold and of sodium, the proportion of which 

 he found to be 14.1 of chloride of sodium, 69.0 of chloride of gold, 

 and 16.6 of water, and the chloride of gold to contain accordingly 

 nearly three times as much chlorine as that of sodium. 



4 Dr. Thomson, who,' says Berzelius in the above paper, * has 

 lately undertaken to determine the atomic weights more accurately 

 than others, was also led to the examination of that of gold*, the oxide 

 of which he found to consist of one atom of gold and three atoms of 

 oxygen, and the chloride of one atom of the oxide and two of muriatic 

 acid. The analysis of the oxide corresponds with my own ; that of 

 the chloride is evidently erroneous, as may be seen from the decom- 

 position of the salt by heat, where chlorine and oxygen gas are not 

 formed in the proportion of 4 to 1, as would necessarily result from 

 Dr. Thomson's analysis. The compound of the chloride of gold and 

 of sodium is, according to the same chemist, composed of 14.85 of 

 chloride of sodium, 49.51 of gold, 17.82 of chlorine, and 17.82 of 

 water, which is also erroneous ; for if it were correct, the third part 

 of the gold would be precipitated as an oxide, during the preparation 

 of the compound from chloride of sodium and (what Dr. Thomson 

 considers as a muriate) of the oxide of gold ; but, according to his 

 own experiments, such a precipitate is not formed. He concludes, 

 however, that I am wrong in supposing that hydracids decompose 

 oxidized bases, and that the muriate of gold gives a striking proof 

 of the incorrectness of my ideas, as the oxide in this salt contains a 

 third more oxygen than could be united to the hydrogen of the acid. 



* After this rapid sketch of the previous labours on the subject, I 

 come to my own analyses, which were made in. the presence of 

 Mr. Johnson, a pupil of Dr.' Thomson's. ' 



* Transact, of the Royal Soc. of Edinb., vol. xi. ; p. 23. 



