NO. III. PHARMACEUTICAL PREPARATIONS. 479 



Both kinds, when quite cold, should be put into pots, and preserved from 

 the external air as much as possible by means of oiled bladder, and should 

 be securely tied over and kept in a dry place. 



INFUSIONS. 



Infusions are solutions of vegetable matter, obtained by maceration either 

 in cold or in boiling water. Infusions by hot water are generally stronger, 

 but sometimes not so grateful as those made by cold. The vegetable to be 

 acted on, if recent, must be cut or bruised, and if dry, coarsely powdered 

 only ; the ingredients should be placed in a pitcher-shaped vessel which can 

 be closely covered, and the proper quantity of soft boiling water should be 

 poured over them. A metallic tea-pot is a convenient vessel for the purpose. 

 The maceration may continue for half an hour, an hour, or several hours, 

 according to the nature and texture of the article, and sometimes the vessel 

 should be placed near the fire ; the infusion should then be strained 

 through tow or fine linen. Infusions are taken warm, except occasionally 

 those of rosemary, balm, mint, &c The general proportion for infusions 

 may be considered as half an ounce to a pint of water. 



In forming syrups, we first make a decoction or infusion of the plant of 

 a sufficient strength, and then boil it up with twice its weight of loaf sugar. 

 This operation should be performed over a slow clear fire, when the articles 

 should be allowed to boil very gently, skimming off the scum carefully as it 

 rises. If the syrup should require clarifying, it is easily done by beating 

 up to a froth the white of an egg^ with three or four ounces of water, and 

 boiling the mixture for a few seconds with the syrup, when the impurities 

 will all rise in a scum, which can be very readily separated. 



Syrups should be preserved in a place the temperature of which never 

 exceeds 55° Fdhr. 



TINCTURES. 



This term is applied to spirituous solutions of vegetable substances in 

 a dried state. Proof spirit is generally employed, but rectified spirit or 

 alcohol is occasionally used. The ingredients are to be macerated in the 

 spirit in a temperature not exceeding 80°, and should be prepared in 

 closely- stopped glass vessels, which should be frequently shaken during 

 the process. The usual period for maceration is fourteen days, at the 

 end of which time the tinctures should be poured off, the residuary in- 

 gredients squeezed, and the whole filtered through blotting paper, and kept 

 in well-corked bottles. The general proportion is, two ounces of vegetable 

 matter to a pint of proof spirit. For stomachic and tonic tinctures, French 

 brandy is to be preferred. 



