1813.] 



Scisntific Inlellige?ic^\ 



145 



with it burns as if it bad been dipped in a solution of saltpetre. It 

 is scarcely soluble in nitric acid; but muriatic acid dissolves it 

 with facility. This oxide may be procured by the following 

 process : — 



Dissolve gold in a mixture of two parts of muriatic acid and 

 one part of nitric acid. The solution ought to be as nearly 

 neutral as possible. When alkalies, alkaline earths, or alkaline 

 carbonates, are dropped into this solution, no precipitate appears 5 

 but if the liquid be heated, a portion of oxide of gold falls 

 down. The whole oxide is not precipitated, because the muriate 

 of gold has the property of combining with the alkaline muriate, 

 and making with it a triple salt. (See VauqueKn's experiments, 

 Ann. de Chim. Ixxvii. 321.) 



3. Gold cannot be combined directly with sulphur ; yet there 

 can be little doubt that there is an affinity between the two sub- 

 stances ; for sulphuric acid combines with the oxide of gold. It 

 cannot be the addition of oxygen surely, the particles of which 

 repel each other, that occasions the affinity. It must exist 

 between the metal and sulphur. If sulphureted hydrogen gas, 

 or an alkaline hydrosulphuret, be mixed with a solution of gold,- 

 a black powder precipitates. This is a sulphuret of gold, it is 

 Composed, according to the experiments of Oberkampft, of 



Gold lOO'OO 



Sulphur « 24-39 



Either the analysis of the oxides of gold by Berzelius, or this 

 analysis, must be erroneous ; for they do not correspond with 

 each other, it is still farther from agreeing with the following 

 law, which Berzelius has deduced from his experiment : — 



Let 100 parts of any metal be combined with a portion of 

 oxygen sufficient to convert it into a protoxide, and a portion of 

 sulphur sufficient to convert it into a sulphuret. The weight of 

 the oxygen is equal to half the weight of the sulphur." 



But there are sufficient reasons, i think, to set aside this law 

 as inaccurate. At present chemists are generalizing too fast. 

 Generalization is the fashion, and it is often adopted upon very 

 slender grounds. I intend to give a striking proof of this in a 

 succeeding number of this Journal. 



III. Putrefaction, 



Some years ago Gay Lussac announced in the Annales de 

 Chimie, and corroborated his opinion by seemingly decisive 

 experiments, that putrefaction does not take place if atmosphe- 

 rical air be completely excluded. Upon this is founded a well- 

 known method of preserving meat fresh for any length of time. 

 Cut it in fragments, fill a bottle with these fragments^ plunge 

 the bottle up to the neck in boiling water, and^ when boilirig liot^ 



Vol. I. W 11. K 



