174 GZUCOSTDES OTHER THAN TANNINS. 



with which it splits up into sugar and melanthigenin when boiled 

 with a dilute acid. 



The so-called smilacin was also formerly regarded as alb'ed to 

 saponin, hut the researches of Fluckiger^ have shown that under 

 this designation a mixture of substances has been described, the 

 principal constituent of which was named pariUin. This body 

 stands in close relation to sapogenin, the decomposition-product 

 of saponin ; and as the latter is contained in sarsaparQla,^ it is 

 probable that parillin is produced from it during the life of the 

 plant. According to Fliickiger, parillin is not soluble in cold water 

 to any appreciable extent but dissolves in 20 parts of boiling. It 

 is taken up by spirit of sp. gr. 0'83 more easily than by stronger 

 or weaker alcohol.* Its reaction with cone, stdphuric asid re- 

 sembles that of saponin. Boiled with 10 per cent, sulphuric acid 

 it decomposes into sugar and parigenin, with production of a 

 green fluorescence. A similar fluorescence is also observed when 

 hydrochloric acid gas acts upon a solution in a mixture of chloro- 

 form and alcohol. 



Swpogmin resembles parillin in most of its properties. Boch- 

 leder is of opinion that it still retains a httle sugar, and is there- 

 fore really the result of an incomplete decomposition of saponin. 

 The violet colouration gradually produced when sapogenin is 

 dissolved in eonc. sulphuric acid serves to distiiigjush the body 

 from digiioresin, which, according to Schmiedeberg, yields a yellow 

 solution. (See § 155.) 



Irtdkan may also be mentioned here, as, although it is not a 

 substance that can be unconditionally ranked as a glucoside, it 

 may nevertheless be compared with them as regards its constitu- 

 tion. By the decomposition of indican indigo- blue is produced, 

 together with a land of sugar called indiglucin, I leave it^ how- 

 ever, an open question whether the formation of indigo-blue is 

 preceded by that of indigo-white, which, it is true, readily yields 

 that substance by absorption of oxygen. Indican appears to 

 occiir in many plants (leaves, etc.), but to undergo a partial 

 decomposition when they are slowly dried, and the black or blue 



1 Compare Tlfickiger aud Hanbuty, ' Pharmacographia,' 645. 



« Otten, ' Histiol. Untera. der Sarsaparillen/ Diss. Dorpat, 1876. Otten 

 estimated the saponin by the methods given in § 78. 



s Arehiv d. Pharm. [3], x. 536, 1877 IPharra, Journ. and Trans, [3], viii. 

 488). 



