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According to Bergman, loo grains metallic lead would afFord 

 143 of vitriol of lead. 



According to Wenzel 143,33. 



According to Wolfe 137,5. He precipitated the nitrous folu- 

 tion of lead by vitriolated tartarin, and probably did not apply 

 enough, or this fait did not difengage the laft portions of the ni- 

 trated lead, or fome part of the vitriol of lead remained in the ni- 

 trous acid. This laft fuppofition is highly probable. 



Vitriol of Copper. 



100 grains of this fait, perfedly cryftallized, loft 28,5 by expo- 

 fure to a heat of 370**. 



Br precipitation with muriated barytes they afforded gi of ig- 

 nited barofelenite, and hence contain 28,5 of water of cryftalliza- 

 tion and 30,33 of real vitriolic acid; and confequently about 40 of 

 calx of copper = 32 of metallic copper. 



Vitriol of Zinc 



100 grains of vitriol of zinc, cryftallized in needles, loft in a 

 heat of 375* 39 grains; and 100 grains of the fame cryftals, being 

 diffolved and treated with muriated barytes, afforded 61,24 of 

 ignited barofelenite, and hence contain 20,414 grains of real vitrio- 

 lic acid. 



CHAP. 



