130 



APPENDIX 



found to be Pararabin. The gum contained 16-6 percent, water, 

 and yielded SSS per cent. ash. 



Mr. Maiden draws attention to the fact that Pararabin is the 

 chief constituent of the vegetable Jellies known as Agar-agar, a 

 Ceylon moss, both of which are used by the natives of India as an 

 article of diet like Sterculia gum, and are supposed to be very 

 strengthening. 



A sample of gum said to be from CocJilospermum gossypium was 

 found by him to be similar to that of Sterculia, but as it had pieces 



bark 



LINE.^. 

 Linamarin 



A. Jorissen and E. H 



germs 



usitatissimuni. The germs, coarsely powdered, were treated repeated- 

 ly with boiling 94 per cent, alcohol, the latter recovered and the 

 residue taken up with warm water.' The resin and fat are 

 separated, and the aqueoits solution treated with a slight excess of 

 lead acetate. After filtration and precipitating the lead with H^'S the 

 liquid is evaporated to a syi-upy consistency. This residue is extract- 

 ed with boiling alcohol, the solvent recovered for the greatest part, and 

 the remaining liquid mixed with ten times its volume of ether under 

 constant agitation. The residue remaining on distilling ofP the ether 

 is taken up with water and this solution concentrated. Standing over 

 sulphuric acid for some time, the concentrated solution is converted 

 into a crystalline mass of linamarin. For purification it is again 

 treated with ether and alcohol as above. Lastly, the principle is 

 dissolved in two parts of warm absolute alcohol, and the solution 

 cooled under agitation. The germs yield about I'S per cent, of 

 the glucoside, which forms colourless needles possessing a refreshing 

 but very bitter taste, is soluble in water and alcohol, but almost in- 

 soluble m ether. Concentrated sulphuric acid "does not colour it ; dilute 

 mineral acids decompose the glucdside into hydrocyanic acid, a fer- 

 mentable sugar reducing Fehling's test, and a volatile compound 

 possessmg some characters of ketones, and giving with iodine and 

 potassium hydrate the iodoform reaction. Boiling barium hydrate 

 liberates ammonia. Linamarin contains C 47-88 per cent.. H 6-68 

 ^er cent N 5-55 per cent., O 39-89 per cent. {Am, Journ. Pharm., 



