152. Detonation of Zinc. [Book VI. 



latter re-difiblves the precipitate if it is added in 

 excefs. 



Zinc has the property of decorrpofing feveral neu T 

 tral falts. If it is confiderably heated with vitriolated 

 tartar in a crucible, it decompofes the fait, and forms 

 a liver of fulphur, in the fame manner as the regulus 

 of antimony does. In this experiment the metal feizes 

 the oxygen of the vitriolic acid, and the acid pafles 

 into the ftate of fulphur, which the alkali diflblvcs. 

 The hepar formtrd by this combination diflolves a 

 portion of the calx of zinc. All the vitriols are like- 

 wife decompofed by zinc. 



When pulverized zinc is added to fufecl nitre, or 

 projected together with that fait into a heated cruci- 

 ble, a very violent detonation takes place. The acti- 

 vity of the inflammation is fuch, that portions of burn- 

 ing matter are thrown to a diftance out of the crucible, 

 in fuch a manner as to require precaution on the part 

 of the operator. Only imall quantities of die mixture 

 fhould be call into the crucible at once The zinc 

 bums by the affiftance of the oxygenous gas afforded 

 by the nitre, and is afterwards found in a ealciibrm 

 flate, more or lefs perfect, according to the propor- 

 tion of nitre ufed. Part of the calx combines with the 

 alkali, and forms a compound ibiuble in water. 



Zinc decompofes common fait, and alfo fal ammo- 

 niac, by feizing the marine acid. The filings of zinp 

 alfo decompofe alum when boiled in a folution of that 

 fait. 



The relation of zinc to fulphur is remarkable, as it 

 is the .only metal which does not unite with it in a re r 

 guline ftate. M. M-orveau, however, has difcovered, 

 that the calx of zinc unites eafily with fulphur by 

 fufion. 



The regulus of zinc is capable of being united with 



that 



