170 FRAXINUS OENUS 



the quantity of which, in the best varieties varies from 70 to 80 

 per cent., but the inferior sorts sometimes only contain about 

 60 per cent. A kind of sugar (dextro-glucose) is also present in 

 manna, sometimes to the extent of 16 per cent., the fatty 

 inferior mannas having the most. Manna likewise contains a very 

 small quantity of a red brown resin with a sub-acrid taste and 

 very unpleasant odour ; and a faintly astringent, bitter, crystalline 

 substance, called fraxin, which closely resembles jffisculin, and to 

 the presence of which the fluorescence of an alcoholic solution of 

 manna is due, as well as the greenish colour of some pieces of 

 manna. The laxative constituent has been ascribed to extractive 

 matter, and to the resin, but mannite possesses in itself similar 

 properties to manna, and it is therefore doubtless to this that the 

 medicinal property of manna is essentially, if not entirely, due. 



Medical Properties and Uses. Manna is a mild laxative. It 

 is especially suitable for children and delicate persons ; and also 

 as an adjunct to more active aperients, in order to assist their 

 action, and to disguise their disagreeable taste. Manna is, how- 

 ever, far less used in this country than formerly. Mannite pos- 

 sesses similar laxative properties to that of manna, and is fre- 

 quently employed on this account in Italy. 



Per. Mat. Med., vol. ii, part 1, p. 671 ; U. S. Disp., by W. & B., 

 p. 547 ; Pharmacographia, p. 366 ; Hanbury, in Pharm. Journ., 

 vol. xi, 2nd ser., p. 326, and vol. iii, 3rd ser., p. 421 ; Stettner, 

 in Archiv der Pharm., vol. iii, p. 194; Pharm. Journ., vol. ix, 

 1st ser., p. 283; Hooker's Journ. of Bot., vol. i, p. 124; Cleg- 

 horn, in Trans. Bot. Soc. of Edin., vol. x (1868-69), p. 132 ; 

 Buignet, in Journ. de Pharm., vol. vii (1867), p. 401, and vol. 

 viii (1868), pp. 5-16. 



DESCRIPTION OF PLATE. 



Drawn from a specimen in Kew Gardens ; the fruit from an oriental speci- 

 men in the British Museum. 1. A flowering branch. 2. A fully expanded 

 flower. 3. Unopened anthers. 4 and 5. The calyx and pistil. 6. Vertical, 

 and 7. Transverse section of the same. 8. Fruit. 9. Vertical section of the 

 same and of the seed. 10. Fruit with a part of the pericarp removed, showing 

 the ripe seed and the aborted ovules. 11. Transverse section of seed. (2-7, 

 10, 11 enlarged.) 



