4 



preparation of the Tinctura Satuniiiia, a tincture is extracted 

 by rectified spirit from a mixture of acetate of Lead and sul- 

 phat of Iron. Although, from the play of affinities and the 

 solubility of the resulting salts, it appears to the Chemist that 

 this preparation derives its principal efficacy from an acetate 

 of Iron produced by double elective attraction; yet as some 

 of the acetate of Lead appears to escape decomposition,* a 

 process (if I mistake not) mentioned by Glauber, occurred 

 to me as much preferable. This consists in extracting a tinc- 

 ture from a mixture of equal weights of acetate of Kali and 

 sulphat of Iron. Such a medicine has been prepared in 

 Dublin since the year 1787 or 1788, and has been fovmd an 

 elegant, agreeable and useful Chalybeate preparation.* 



If the tincture be made Avith common rectified spirit, it 

 grows turbid by keeping, and deposits an oxyd of Iron. I 

 found that this does not happen when Alcohol -f- is employed; 

 and accordingly furnished a formula, for the specimen of the 

 Dublin Pharmacopoeia, printed in the year 1794, in which 

 Alcohol is directed to be used. Some time afterwards it was 

 observed ( I believe, first, by Mr. Watts, an intelligent and 

 correct Apothecary in this city) that a tincture, retaining its 

 transparency on keeping, may be extracted by rectified spirit 



from 



* The Tinctura Saturnina affords an insoluble precipitate by the addition of 

 marine acid. 



t A teaspoonful or two may be conveniently taken in asses milk. 



J That is, vinous spirit of spec, gravity ,815. — This explanation is neces- 

 sary, as from the less restrained use of the term, in the Pljarmacopoeia of 

 the Edinburgh College no inconsiderable degree of confusion has affected direc- 

 tions for Pharmaceutical preparations, particularly of that now treated of. 



