Intelligence and Miscellaneons Articles. 461 



then the muriatic acid precipitated by silver : the chloride of silver 

 weighed 34-65 grains, equivalent to 8-453 grains of chlorine, or 8-78 

 grains of muriatic acid. "Thus it appears," says Dr. Thomson, "that 

 24-2 grains of gold, in the state of peroxide, had been combined with 

 887 grains of muriatic acid. Consequently 25 grains of gold in the 

 state of peroxide must be united with 9-1 1 grains, of muriatic acid. 

 This is only 014 grain less than 9-25, the equivalent for 2 atoms of 

 muriatic acid. From this result it is obvious, that muriate of gold is 

 a compound of 2 atoms muriatic acid, and 1 atom peroxide of gold : 

 the weight of the dry salt having been 42-8 grains, it is clear that it 

 must have contained 5 atoms of water, and that muriate of gold is 

 composed as follows : 



2 atoms muriatic acid <)'25 



1 atom peroxide of gold 28- 



5 atoms water 5-625 



42-875 



"The precipitation of the gold by protosulphate of iron seems to 

 show, that the gold in this salt is in tlie state of oxide, and conse- 

 quently combined, not with chlorine, but with muriatic acid. It is 

 equally clear that, in the sodium chloride of gold, the metal is not 

 oxidized but in the metallic state, and united to chlorine. Hence the 

 reason why it is so difficult to reduce the gold from the sodium chloride 

 by heat, while it is so easy, by a very moderate heat, to reduce the 

 gold from the muriate. 



" Gold furnishes a striking example of the want of coincidence in 

 the proportions of oxygen and chlorine, which unite with bodies, and 

 of the danger of being misled, when we infer the composition of a 

 chloride from that of an oxide. The peroxide of gold, containing 3 

 atoms of oxygen, one would have been disposed to infer, that the 

 chloride would also contain 3 atoms of chlorine ; yet it contains only 2 

 atoms. This want of coincidence between the peroxide and chloride 

 of gold, is probably the reason why the muriate of gold cannot be con- 

 verted into a chloride by heat ; at least all my attempts to obtain a 

 chloride by this process have ended in disappointment. In what man- 

 ner the change takes place in the atomic proportions, when common 

 salt is added to the muriate, it is not easy to conceive ; but the ex- 

 periments which I have related in this paper, and in my "Attempt," 

 leave, I conceive, no doubt that the conversion from muriate to chloride 

 actually takes place." — Trans. Royal Soc. Edinburgh, vol. xi. p. 23. 



SUPPOSED NEW VEGLTO-ALKAI.I — CHINIOIDIA. 



In the last Number but one of the Piiil. Mag. we noticed Dr. 

 Serturner's supposed discovery of a new vegeto-alkali, to which he 

 gave the name of Chinioidia. MM. Henry, jun. and Uelondre have 

 made numerous experiments to determine whether such an alkali 

 really exists, and they have arrived at the following conclusions : — 



1st. That tiiere remains little doubt as to the non-existence of chi- 

 nioidia, and that it ap|)cars demonstrated that it is only a modification 

 of quina and cinclionia combined and rendered uncrystallizablc by a 

 peculiar yellow matter. These inodilKulioiis cease, when after a long 



time 



