- 
_ COMPOSITA. Sly 
separated by layers of thin-walled and axially elongated 
parenchyma. The meditullium has no medullary rays, and 
consists mainly of ducts varying in diameter and more or less 
interspersed with thin-walled, elongated cells. 
After frost and early in the spring the root is sweet; scent 
the spring aud summer the milk-juice becomes thicker and the 
bitter taste increases ; the root is, therefore, directed to be 
collected late in the autumn. The spring root yields a 
biiterish-sweet extract. Bentley regards the root collected 
about July as most efficient. (Stillé and Maisch.) The annual 
root as cultivated in India is very much smaller. 
Chemical composition.—The bitter principle, Tarawacin, was 
obtained by Polex (1839) in a crystalline state by treating the 
milk-juice with boiling water and evaporating. Kromayer 
(1864) found it necessary to leave the aqueous solution in con- 
tact with animal charcoal, from which afterwards alcohol dissolv- 
ed the-bitter principle, requiring treatment with lead acetate 
_ and sulphuretted hydrogen to free it from colouring matter and 
other principles. Kromayer obtained taraxacin as° an amor- 
phous bitter mass. The milk-juice contains also resin and 
taraxacerin, C®°H'O, which is insoluble in water, crystallizes 
from hot alcohol, and when in an alcoholic solution has an acrid 
taste. The dry root yields from 5 to 7 per cent. of ash. 
Dandelion root collected in autumn is rich in inulin. Dra- 
| gendorff (1870) obtained from the root collected in October 
24 per cent. of inulin and a little sugar, but when collected in 
March only 1-74 per cent. of inulin was found, and about 18 
per cent. each of uncrystallizable sugar and levulin, the latter 
being intermediate between inulin and sugar in having the 
composition of inulin, Lut being of a sweet taste, soluble in 
cold water, and without influence on polarized light. Frick- 
- hinger (1840), Widemann, and others had obtained notable 
quantities of mannit from the concentrated juice of dandelion, 
but T. and H. Smith (1849) proved that this principle does 
not pre-exist, and that, on the sone: itis a pene eg a 
from fermentation. 
