in Lead and its Compounds, 129 



Exp. XIII. Sample purchased at Mr. Caplin's, 42 Great Pul- 

 teiiey Street (in powder and small lumps). 6000 grs. mixed 

 with 300 grs. of powdered charcoal and reduced in a Cornish 

 crucible^ gave of lead 5310 grs. Of this lead, cupelled 2000 grs., 

 treated the small remaining button of silver with nitric acid, and 

 obtained a minute trace of gold. 



Exp. XIV. Sample brought from Birmingham (in small, thin 

 scales). Reduced 2880 grs. with 150 grs. of powdered charcoal 

 in a Cornish crucible ; lead obtained weighed 2270 grs. Of this 

 lead, cupelled 2000 grs. ; the small button of silver obtained, 

 parted with nitric acid, left a minute trace of gold. 



White Lead. 



Exp. XV. Specimen purchased at Mr. Button's, Holborn 

 Bars, sent as " pui-e carbonate of lead," and said to have been 

 prepared by precipitation from a solution of the nitrate of lead 

 by carbonate of soda. 6000 grs. mixed with 200 grs. of pow- 

 dered charcoal and heated in a Cornish crucible, gave of reduced 

 lead 4190 grs. Of this lead, cupelled 2000 grs., left a very 

 minute button of silver ; parted by nitric acid, a just perceptible 

 ti'ace of black matter remained undissolved, but no distinct me- 

 tallic lustre could be obtained by bm'uishing. 



Exp. XVI. Repeated Exp. XV. 2 lbs. troy (11,520 grs.) 

 reduced by heating in a Cornish cracible with 400 grs. of char- 

 coal, gave of lead 8550 grs. Of this lead, 4000 grs. cupelled 

 left a very small button of silver ; parted by nitric acid, left a 

 just percqitible trace of gold. 



Exp. XVII. Sample bought at Mr. G. James's, 72 Wardour 

 Street. 6000 grs. mixed intimately with 200 grs. of powdered 

 charcoal and heated in a Cornish crucible, gave of lead 4340 grs. 

 Of this lead, cupelled 2000 grs., parted the small residual button 

 of silver with nitric acid, and obtained a vei'y minute trace of gold. 



Exp. XVIII. Sample purchased at Mr. Caplin's, 42 Great 

 Pulteney Street. Mixed 6000 grs. with 200 grs. of powdered 

 charcoal, heated the mixture in a Cornish crucible, obtained of 

 lead 3840 grs. Of this lead, cupelled 2000 grs. ; the small 

 globule of silver obtained, parted by nitric acid, left a verij minute 

 trace of gold. 



Oxychloride of Lead. 



Exp. XIX. Pattinson's oxychloride. 1 lb. troy (5760 grs.) 

 mixed intimately with 4 ozs. (1920 grs.) of dried cai'bonate of 

 soda, and ,} oz. (240 grs.) of powdered charcoal, heated the niix- 

 ture in a Cornish crucible, lead obtained weighed 4140 grs. Of 

 this lead, cupelled 4000 grs. (a small portion of the lead was 

 lost during the oj)eration), no button of silver was ()])tained (?). 

 There was not a sufficient quantity of this sample left to repeat 

 the experiment. 



