1 82 Analysis of ilte Scammoniesfrom 



it with that of some other milky and acrid plants, and 

 sometimes they increase its weight by the addition of char- 

 coal or other foreign substances. In order to ascertain 

 that scammony does not contain any of these heterogeneous 

 matters, we ou^ht to break the pieces of the juice, and pick 

 such as are brilliant within, rejecting those which appear 

 too black, burnt, or sandy. 



The scammony of Aleppo is light, of an ash gray, bril- 

 liant and transparent in its fracture. That of Smyrna is 

 very compact, heavy, and of a deeper colour : it is also more 

 difficult to reduce into powder than that of Aleppo. 



Examination of the Scammony of Aleppo. — When the 

 scammony is pure, it melts entirely on a plate of heated 

 iron, and gives out nauseous vapours : when pounded in 

 water, the liquor is of a milky whiteness. 



Boiling water makes it run into a mass. The liquor be- 

 comes yellow^ has a bitter taste, and is neither alkaline nor 

 acid, which proves that this substance is not adulterated 

 with ashes, as some authors assert. 



Alcohol at 40 degrees forms a slight precipitate in this 

 aqueous liquor, and with the acetate of lead we obtain yel- 

 lowish flakes soluble in the nitric acid. 



The alcoholic tincture of scammony is of a brownish yel- 

 low colour. This liquor reddens turnsole tincture : there 

 remains, after the evaporation, a resin of a yellowish whit& 

 and transparent. 



This resin is entirely dissolved in the nitric acid, which 

 is coloured yellow. The addition of water slightly dis- 

 turbs the liquor. 



This substance is equally soluble in a solution of pure 

 potash, even cold, and the liquor acquires a yellow colour: 

 if this solution be made with the help of heat, the colour 

 is brown. Water even in great quantity does not precipi- 

 tate resin. Even when saturated by the muriatic acid, it 

 does not separate the resin. This triple compound of 

 resin, acid, and potash, ought to excite the attention of prac- 

 titioners : it would perhaps be possible in this way to find 

 a solvent for resins which water does not afTect. 



That part of scammony which is insoluble in alcohol, 

 when dried, acquired a gray colour. 



When treated with boiling water, it coloured it yellow, 

 and alcohol precipitated it in white flakes. 



In order to determine the proportion of the constituent 

 principles of the scammony of Aleppo, we took 100 parts 

 of this substance, which we dissolved in alcohol : the liquor 

 was coloured yellow. There remained, after the treatment 



by 



