^64 Decompo/itian cf the Acetite of Lead, ^c. 



Examination of the Liquor 'with fome Reagents^ 



ift, The liquor taken from the jar was colourlefs and per- 

 fe6lly tranfparent. 



ad, It. gave a ftrong green tint to blue vegetr.ble colours. 



3d, When tried with verv pure fulphuiic acid it formed 

 no precipitate, which convinced me that it held in foknion 

 no lead. 



4th, A portion properly evaporated furniflied fmall cryftals 

 of acetite of zinc in argenteous leaves, which afi"e6led no re- 

 gular form. 



5th, Ammonia produced in it a white flaky precipitate, 

 not very abundant. At the moment even of contaft there 

 is emitted a itrong odour of flour pafl;e, which is fpeedily dif- 

 lipated bv agitation. 



6th, This precipitate at the end of fome hours had ac- 

 quired a femi-gelatinous confiftence, and the addition of a 

 new quantity of alkali rediflx)lved it in part. 



7th, The carbonates of potafli. foda, and ammonia, formed 

 in it white precipitates more or lefs abundant. 



8th, Lime water recently prepared precipitated from it the 

 zinc in the ftate of a white oxide, paler and more homoge- 

 neous than the preceding. 



9th, The precipitate obtained by carbonate of potafti, 

 waihed feveral times with diftilled water, and carefully dried, 

 was exceedingly white and light. 



10th, Being brought into contatt with concentrated ful- 

 phurous acid, it diflblved in it completely, with a difengage- 

 iTient of carbonic acid, and a total difappearance of the ful- 

 phurous odour ; which feems to (how a very great relation 

 between the new fait refulting from this combination and the 

 fulphate of zinc, for the difcovery of which we are indebted 

 to Vauquelin and Fourcroy. 



KECAPITULATION. 



It refults from thefe fafts, ift, That the decompofition of 

 the acetite of lead by zinc exhibits feveral phaenomena not 

 obferved in that of other falls and metallic folutions by the 

 fame metal. 



2d, That difiilled water fcems to favour this decompofition, 

 as it is eflefted in that fluid a third fooner than in common 

 water. 



3d, That common water may, however, be preferable in 

 experiments of mere curiofity, as it checks the decompofing 

 aftion of the zinc, and difpofes the metallic moleculae to af- 

 fume that arrangement which is peculiar to them; a phae- 

 nomenon which agrees with the laws of cryftallization. 



1 fliall terminate thefe obfervations by propofmg to the 



College 



