266 CENANTHIN GUM. 



glass in order to prepare its cenanthin; particularly 

 as Faure is convinced that cenanthin cannot be preci- 

 pitated by tannic acid which is soluble in alcohol, 

 in which cenanthin is insoluble. 



Besides this, it is extremely difficult, if not impos- 

 sible, to add only just so much isinglass as is neces- 

 sary to precipitate tannic acid; an excess would 

 adulterate the cenanthin with gelatine. 



Disregarding, therefore, his suggestions,! evaporated 

 the wine, precipitated the residue with alcohol, dis- 

 solved the precipitate in water, and re-precipitated it 

 in alcohol, and this process I repeated several times. 



I obtained every time a powdery precipitate, and 

 as the colour was principally absorbed by the spirit it 

 became paler every time. 



Prom this powdery precipitate a coherent mass 

 could be collected, whilst the crystalline precipitate 

 of the salts again separated a quantity of viscid mat- 

 ter which was again obtained when the crystalline 

 precipitate was re-dissolved in a little water, and 

 precipitated with a little alcohol. 



As soon as the viscid substance was obtained it was 

 purified, that is, it was dissolved in a little water, and 

 a little alcohol added to free it as much as possible 

 from the salts, tannic acid, and colouring matter 

 which were mixed with it. After this treatment had 

 been repeated several times, it was as pure as it is 

 possible to procure it in this manner. 



The quantity of cenanthin found in ordinary Bor- 



