VEGETABLE ALKALIES. 91 



are generally insoluble in water, but dissolve in hot alcohol. Their 

 taste in solution is usually intensely bitter, and their action on the 

 animal economy, very powerful, in consequence of which they are 

 of the greatest value as medicines, containing, as they do, the most 

 active properties of the plants in which they are respectively found. 

 They all contain nitrogen, and are complicated in their constitution, 

 having high combining numbers. 



The number of these bodies is very large ; only the most impor- 

 tant will be here noticed. 



Morphia, — the active principle of opium ; — exists in it as a 

 meconate; procured from an infusion of opium by means of ammo- 

 nia which throws down the morphia, leaving the meconate of ammo- 

 nia in solution. It forms small shining crystals, which are colourless ; 

 nearly insoluble in water ; soluble in hot alcohol ; forms soluble 

 salts with the acids, the most important of which are the sulphate^ 

 muriate, and acetate. 



Narcotina, — exists also in opium ; it is separated from the other 

 principles by boiling ether, which yields it on evaporation. 



Codeia, — exists in opium as a meconate; forms colourless crystals, 

 rather more soluble in water than morphia. Codeia forms salts 

 with the acids. 



Other principles found in opium are Paramorphia or Thehain, 

 Pseudommyhia, and Narceia, besides Meconic acid, whi<;h has 

 already been alluded to. 



Qiiinia and Cinchona, — the active principles of Peruvian bark; — 

 exist in it in combination with kinic acid ; procured from an in- 

 fusion of bark by the action of quicklime, which combines with the 

 kinic acid, liberating the alkalies ; these are then to be taken up by 

 boiling alcohol, and decolorized by animal charcoal. 



Quinia occurs as a whitish powder ; it does not crystallize. Cin- 

 chona is in the form of minute crystals. Both are very insoluble 

 in water, but dissolve in boiling alcohol. Their most important 

 salts are the sulphates, which are soluble in water. 



Strychnia and Brucia, alkalies existing in the Strychnos nux 

 vomica, St. Ignatius' bean, and false Angustura bark : they are 

 associated with igasuric acid, 



Ver atria, — the alkaline active principle of the Veratrum sabadilla, 

 and of the Yeratrum album, or white hellebore. 



Emetia is the alkaline principle of ipecacuanha. Colchicina, — 

 the active principle of the Cohhicuon autumnale. Solania, — the 

 alkali of the Solanutn dulcamara. Caffeia, or Tkeine, — the active 

 alkaline principle found both in coffee and tea. 



We have also Atropia, from belladonna ; Aconitia, or Aconitine, 

 from aconite ; Daturia, from stramonium ; Coneia, from hemlock ; 

 Nicotina, from tobacco, &c., &c. 



