190^ Extenjive Effects off be Polfon of Lead. [Book VI ; 



liquor, put one hundred and twenty grains of this pow- 

 der, and one hundred and eighty grains of cream of tar- 

 tar, into a very ftrong bottle, fill it with water, let it boil 

 for an hour, and then cool. Cork the bottle, and fre- 

 quently fhake up the ingredients. After it has flood 

 for fome hours to fettle, pour off the clear liquor, and 

 put it into little bottles, which contain about an ounce, 

 having previoufly dropped into each twenty drops of 

 marine acid. Cork them clofe by means of wax 

 mixed with a little turpentine. One part of 'this li- 

 quor, mixed with three parts of the wine fuppofed to 

 contain noxious metallic particles, will difcover, by a 

 black precipitate, the fmalleft particle of lead or cop- 

 per, but will not affect the iron contained in it. Pure 

 wines are not difcoloured by the addition of this 

 liquor. 



The deleterious effects of lead are not confined to 

 its action on the flomach. Men who work in the 

 manufactories for the different preparations of lead 

 are liable to complaints very fimilar to thofe who drink 

 liquors containing lead. Painters are fo liable to this 

 complaint, from the lead contained in paint, that it 

 has obtained, on this account, the name of the pain- 

 ter's colic. 



Lead is the moft powerful article in the materia' 

 medica in retraining hemorrhages and exceflive dif- 

 charges, but its uie is fo dangerous that it is not very 

 often employed internally by phyficians. Yhe prepa- 

 rations of lead are, however, highly beneficial, without 

 being generally dangerous, as ingredients in plafters 

 and other external applications, particularly in the well 

 known Goulard's extract. 



The calces of lead are ufed in making fome kinds 

 of glafs, of which they increafe the folidity, and to which 

 they impart a kind of unctuofity which fits them for 



being 



