CRUDE DRUGS. 687 



Inner Structure. — See Fig. 297. 



Constituents. — An active, amorphous substance, filicic 

 ACID, 2 to 8 per cent., being contained apparently in greatest 

 abundance in rhizomes collected in autumn, and readily decom- 

 posing with the formation of an inactive but crystalline anhy- 

 dride; and FILICIC anhydride (filicin, or so-called crystalline 

 filicic acid). The latter occurs from 19 to 31 per cent, in the 

 drug, and may be converted into filicic acid by dissolving in alka- 

 lies and precipitating with acids. The drug also contains from 

 0.025 to 0.045 per cent, of a light yellow volatile oil with an 

 intense odor of the drug and an aromatic, burning taste. It con- 

 sists of free butyric and allied acids and hexyl and octyl esters of 

 the fatty acid series, ranging from butyric acid to pelargonic. 

 From 6 to 7 per cent, of a green fixed oil is present, which con- 

 sists of the glycerides of filixolic and filosmylic acids, the latter 

 being volatile. Among the other constituents are a small amount 

 of a bitter principle ; about 10 per cent, of filixtannic acid ; a soft 

 black resin and a hard red resin ; about 1 1 per cent, of an uncrys- 

 tallizable sugar ; starch, and 2 to 3 per cent, of ash. 



Allied Plants. — The rhizome of Aspidium spinulosiim 

 appears to possess properties similar to the official drug; it some- 

 what resembles that of A.Filix mas, but the chaffy scales possess 

 marginal glandular hairs and the number of fibrovascular bundles 

 in the rhizome is usually but 6 or 7. 



Adulterants. — The rhizomes of other ferns are sometimes 

 substituted for those of the true drug. The botanical origin of 

 these substitutes is not clear. A very common substitute is shown 

 in Fig. 277a, C, which is supposed to be derived from Osmunda 

 Claytoniana or a related species. It occurs in large pieces with 

 coarse, wiry .roots, flattened stipes and is free from chaflfy scales. 



CHONDRUS.— IRISH MOSS OR CARRAGHEEN.— 

 The entire plant of Chondrus crispus (Fam. Gigartinacese), a 

 red alga (Figs. 9; 278) found along the northwestern coast of 

 Ireland and the coast of Massachusetts (p. 16). The plants 

 are collected chiefly during June and July, spread out on the 

 beach and bleached by the action of the sun and dew, then treated 

 with salt water, finally dried and stored. The chief points of col- 

 lection in this country are 15 to 25 miles south of Boston. 



