

TINCTURES 733 



Spirit of ether is used in the preparation of tincture of 

 lobelia, and solution of ammonia, in making the ammoniated 

 tinctures of guaiacum, valerian, ergot, opium, and quinine. 

 Tinctures are prepared without heat by simple solution, by 

 maceration, or by displacement, or sometimes by a combina- 

 tion of these processes. The materials, first reduced by 

 cutting or bruising, are placed with the spirit in a suitable 

 vessel, and usually remain from two to seven days ; the 

 solution is poured off, the residue pressed, and the tincture, 

 when filtered, is ready for use. Sometimes the materials, in 

 a state of moderately fine division, are packed in a per- 

 colator or cylindrical vessel of glass earthenware, or metal ; 

 the spirit passes gradually through them, displaces and 

 dissolves out their soluble parts, filters through the linen or 

 calico, which is usually stretched across the lower part of 

 the cylinder, and passes off by the stop-cock, which should 

 be attached to the apparatus. Some tinctures are made by 

 macerating the materials in water for a couple of days, 

 obtaining the remaining active principles by percolation 

 with spirit, and mixing the two solutions. More thorough 

 and rapid extraction of active principles is obtained by 

 Burton's process. The drug and solvent are packed in the 

 percolator, on the neck of which an elastic cap is fixed ; 

 with an exhausting syringe a partial vacuum is created ; and 

 air being subsequently admitted, the spirit penetrates the 

 drug, and more effectually extracts its active principles. 



Tinctures are clear, of a yellow, red, or brown colour, and 

 generally keep well. A few have been standardised, which 

 means that, in accordance with the B.P. 1898, the tincture 

 shall be made to contain a fixed percentage of the chief 

 active principle of the drug. The tinctures of cinchona, 

 jalap, and opium are now standardised, and others are 

 directed to be prepared from standardised extracts. The 

 revisers of the B.P. have endeavoured to reduce dubiety 

 and risk of accident by so adjusting the strength of the 

 tinctures that, for an adult human patient, the average 

 dose of the more potent tinctures is from five to fifteen 

 minims, and of the less potent, from half a drachm to a 

 drachm, while four to eight drachms of the stronger, and 

 one to two ounces of the weaker tinctures may be pre- 



