Analysis of the Scammonies from Aleppo and Smyrna. 1 81 



From the very near approximation of the proportions be- 

 tween the sulphate of barytes and ammoniaco-magnesian 

 phosphate, obtained in the analysis of all these products of 

 sea water, to those which result from the decomposition of 

 two equal quantities of sulphate of magnesia, it may be 

 inferred that they contain no sulphate of soda*., For ex- 

 ample, to decide whether the Scotch salt contains an alka- 

 line sulphate, or not, I dissolved 1500 grains in a pint of 

 boiling water, and evaporated till fourteen drachm measures 

 only remained, the common salt being removed as soon as 

 it was formed. The residuary liquid was divided into two 

 equal portions, one of which gave \S\ grains of sulphate 

 of barytes, and the other, 14 grains of ammoniaco-mag- 

 nesian phosphate. The proportion between these numbers 

 is so nearly that which has been already assigned, (viz. 112 

 to 90,) that we may safely infer the total absence of sul- 

 phate of soda. This salt, indeed, is considered as incom- 

 patible with muriate of magnesia; but after digesting, for 

 two or three days, 100 grains of the former, with 20 of the 

 latter, evaporating to dryness, and washing the residuum 

 with repeated affusions of alcohol, I found that two grains 

 of the muriate of magnesia had escaped decomposition. 



Manchester, June 19, 1809. 



XXXIIP. Analysis of the Scammonies from Aleppo and 

 Smyrna; to which are subjoined some Observations on the 

 red Colour given to Turnsole by the Resins. By Messrs, 

 Bouillon Lagrange and VoGELf. 



J_ he two species of scammony in question are procured 

 from the root of a plant which grows in Syria. It seems 

 that il is by an incision made in the root that the juice is 

 extracted ; each root yields about two drachms. only. The 

 juice thus extracted is dried in the sun, and then exposed 

 for sale : at least it is in this way that the finest and purest 

 scammony is obtained. Frequently, however, the inhabitants 

 of Syria and Natolia, in order to procure a greater quantity 

 of the sap, extract it by expression, not only from the 

 root, but from the stalks and leaves: occasionally also they 

 adulterate the scammony by mixing the juice procured from 



* l employed more attention in investigating the presence of sulphate of 

 soda in the products of sea water ; because this salt is stated to be one of its 

 ingredients by the Bishop of Llandaff, (Chemistry, vol. ii. p. 62,) and by 

 other chemical writers. 



f Annates dc CUimie, tome lxxii. p. 69. 



M3 it 



