PHARMACY. 



a large quantity of water. The resin, in- 

 capable of remaining 1 dissolved in the 

 watery liquor, separates and falls to the 

 bottom, leaving in the menstruum such 

 other principles of the plant as the spirit 

 might have extracted at first along with 

 it. But this is only practised for the pur- 

 pose of analysis. 



Extracts made -with Water only. 



Extractum gentian ?e lutea, Edin. ex- 

 tract of gentian. Having cut and bruised 

 any quantity of gentian, pour upon it 

 eight times its quantity of water. Boil to 

 the consumption of one half of the li- 

 quor, and strain it by strong expression. 

 Evaporate the decoction immediately to 

 the consistence of thick honey, in a bath 

 of water saturated with muriate of soda. 



In the same manner are prepared ex- 

 tracts 



Of the roots of liquorice, extractum 

 g'lycyrrhizje glabrae. 



Of the roots of black hellebore, extrac- 

 tum hellebori nigri. 



Of the leaves of rue, extractum rutse 

 graveolentis. 



Of the leaves of senna, extractum cassiae 

 sennze. 



Of the flowers of camomile, extractum 

 anthemidis nobilis (chamcemeli.) 



Of the heads of white poppy, extrac- 

 tum papaveris albi. 



Of logwood, extractum hxmatoxyli 

 Campechensis. 



Extract of broom tops, extractum ca- 

 cuminis genista;. 



Extract of camomile, extractum cha- 

 $ smelt. 



Extract of savin, extractum sabinae. 



The other extracts^ of this division are, 



Extractum cinchonae, Loncl. extract of 

 Peruvian bark. 



Extractum hxmatoxyli, Load, extract 

 of logwood. 



Extractum opii, Uubl. extract of 

 opium. 



Extractum senna:, Lond. extract of 

 senna. 



Extracts made with Jllcohoi and Water. 



Extractum cinchonas officinalis, Edin. 

 extractum cinchona; cum resina, Lond. 

 resin of bark. 



Extractum radicis convolvuli jalapre, 

 Edin. extractum jalapii, Lond. resin of 

 jalap. 



Extractum cascarillcc, Lond. resin of 

 -cascarilla. 



Extractum colocynthidis 

 compound extract of colocyntli. 



CLASS XX. Pulveris. POWDEUS. 



This form is proper for such materials, 

 only as are capable of being sufficiently 

 dried to become pulverisable without the 

 loss of their virtue. There are several 

 substances, however, of this kind, which 

 cannot be conveniently taken in powder ; 

 bitter, acrid, foetid drugs are too disa- 

 greeable ; emollient and mucilaginous 

 herbs and roots are too bulky ; pure 

 gums cohere, and become tenacious in 

 the mouth : fixed alkaline salts deliquesce 

 when exposed to the air, and volatile al- 

 kalies exhale. Many of the aromatics, 

 too, suffer a great loss of their odorous 

 principles when kept in powder; as in 

 that form they expose a much larger sur- 

 face to the air. 



The dose of powders, in extemporane- 

 ous prescription, is generally about half 

 a drachm : it rarely exceeds a whole 

 drachm ; and is not often less than a scru- 

 ple. Substances which produce powerful 

 effects in smaller doses are not trusted to 

 this form, unless their bulk be increased 

 by additions of less efficacy ; those which 

 require to be given in larger ones are bet- 

 ter fitted for other forms. 



The usual vehicle foi taking the lighter 

 powders, is any agreeable thin liquid. 

 The ponderous powders, particularly 

 those prepared from metallic substances, 

 requi; e a more consistent vehicle, as sy- 

 rups ; for from thin ones they soon sub- 

 side ; resinous substances likewise are 

 most commodiously taken in thick liquors, 

 for in thin ones they are apt to run into 

 lumps, which are not easily again soluble. 



Pulvis aloes cum canella, Lond powder 

 of aloes with canelia. 



Pulvis aloeticus cum guaiaco, Lond, 

 powder aloetic with guaiacum. 



Pulvis aloeticus cum ferro, Lond. pow- 

 der aloetic with iron. 



Pulvis aromaticus, Lond. Dubl. powder 

 aromatic. 



Pulvis asari compositus, Lond. Dubl, 

 powder ot asurabacca compound. 



Pulvis crctcc compositus, Lond. pulvis 

 carbonatis calcis comp. Edin. powder of 

 chalk, compound. 



Pulvis cretse compositus cum opio, 

 Lond. powder of chalk, compound with 

 opium. 



Pulvis chelarum cancri compositus> 

 Lond. powder of crab's claws, compound. 



