394» Intelligence and Miscellaneous Articles. 



Gold.... 74 in 100 



Azote 9-5 in 100 



These numbers are represented by the formula Au'^O^ + 2(AzH3) 

 + HO, which represents the preceding compound as hydrated, and 

 which requires 



Gold .... 75 in 100 

 Azote . . 10 in 100 

 It can scarcely be doubted that this compound contains water. 



To the above statements M. Figuier has made the following addi- 

 tions, which we translate at length : — 



If to these considerations it be added, that the theory of M. Dumas 

 was proposed at the period in which electro-chemical opinions were 

 in highest favour, and that thus circumstanced he was guided espe- 

 cially by the analogy of the composition then attributed to the amal- 

 gam of ammonium (considered as a combination of azoturet of po- 

 tassium and ammonia) ; and if it also be remarked, that analysis suf- 

 ficiently agrees with this point of view, we shall probably be led to 

 think that the ancient opinion of Proust and Berthollet is still the 

 more probable one. 



I am, however, continues M. Figuier, far from believing that these 

 are the last words which will arise on this occasion. On all occa- 

 sions, when the true nature of a compound containing ammonia is 

 discussed, too much attention and reserve cannot be exerted. Some 

 chemists will be tempted to see combinations of amide in these vari- 

 ous kinds of fulminating gold, others may discover compounds ob- 

 tained by the substitution of oxide of gold for the hydrogen of the 

 ammonia ; but I am of opinion that we ought not to be too much 

 pre-occupied with these questions, which will be naturally resolved, 

 with many others, when we possess more certain knowledge of the 

 constitution of ammoniacal compounds. — Ann. de Ch. et de Phys., 

 Juillet 1844. 



ON THE TEROXIDE OF GOLD. BY M. FIGUIER. 



Analysis of the Protoxide of Gold. — After trying various modes of 

 analysis, such as reducing the oxide by hydrogen, and decomposition 

 by hydrochloric acid, the author ascertained that the mere action of 

 heat on this oxide was the most exact and ready method of analysis. 

 Having determined by previous trial the accuracy of this process in 

 analysing the tritoxide of gold, the author repeatedly found the num- 

 ber indicated by theory within the first place of decimals, and this, 

 moreover, confirms the accuracy of the atomic weight of gold as de- 

 termined by Berzelius. The following is the simple method of ana- 

 lysis adopted : — an indeterminate quantity of the oxide, but amount- 

 ing to nearly 15 grains, was put into a very narrow glass tube, one end 

 of which was blown into a bulb. Allowance was made by calcula- 

 tion for the small quantity of air contained in the tube, and as its ca- 

 pacity never exceeded about 1 '5 cubic inch, it will be seen that the error 

 resulting from the uncertainty of the temperature will entirely disap- 

 pear on account of the smallness of the quantity of the air. The 



