which produces mannose, from the bulb of Liliura. 141 



This was removed, well washed and boiled with water. It dis- 

 solved and on cooling and standing, separated out in rhombic 

 crystalline plates. As finally prepared by crystallization from 

 dilute alcohol it Avas nearly colourless with a melting point of 

 195° — 200°. Dissolved in hydrochloric acid it showed levorotation. 

 Hence it agrees in all respects with mannose-hydrazone. 



The numbers obtained for the opticity and cupric reducing 

 power agree closely with the view that the carbohydrate is one 

 which hydrolyses to mannose. According to Fischer and Hirsch- 

 berger 1 mannose reduces Fehling's fluid rather more strongly than 

 glucose. From their figures the 1*7 grams of copper obtained 

 above are equivalent to 0874 gram of mannose. This amount 

 should give a rotation in the 200 mm. tube of + o, 25 2 , which 

 approaches very near the observed angle + 0°'23. Thus there is 

 little room for doubt that practically the whole of the carbohydrate 

 extracted from the bulb of Lilium candidum by cold water and 

 precipitated by strong alcohol, hydrolyses to mannose. 



The same substance has also been prepared from the bulb of 

 Lilium auratum, and mannose-hydrazone made from it after 

 hydrolysis. 



The bulbs of six other species examined, viz. L. bulbiferum, 

 L. croceum, L. dauricwn, L. lancifolium, L. longiflorum and 

 L. Martagon, contain in their parenchymatous cells mucilage, 

 which is in all probability the same carbohydrate, so that this 

 additional reserve material may be considered a characteristic of 

 the genus. 



Distribution of mannose in plants. A mannose-producing car- 

 bohydrate occurs in certain seeds in the form of reserve-cellulose. 

 Reiss 3 showed that this variety of cellulose is capable of being 

 hydrolysed by strong acids to give a new sugar, which he termed 

 seminose, now reckoned to be identical with mannose. He proved 

 the presence of this mannocellulose in seeds of several palms, of 

 Allium cepa, Asparagus officinalis, Iris pseudacorus, Strychnos 

 nux vomica and Coffea arabica. His results have been confirmed 

 and extended by other investigators. 



Another mannose-producing carbohydrate differing from re- 

 serve-cellulose in being soluble in water and capable of being 

 hydrolysed by dilute mineral acids has been called mannan. Its 

 presence was first proved in the drug, salep, which is prepared 

 from the tuberous roots of certain species of Orchis. The mucilage 

 it contains is converted into mannose on boiling with dilute acids 4 . 



1 Fischer and Hirschberger, Ber. Deut. Chem. Ges. 1889, xxn. p. 365. 



2 [a]D is taken to be equal to + 14°"25, the value obtained by Ekenstein for 

 crystalline mannose. 



3 Eeiss, Ber. Deut. Chem. Ges., 1889, xxn. p. 609. 

 ■> Gans and Tollen, Ibid., 1888, xxi. p. 2150. 



VOL. XI. PT. II. 11 



