OILS AND OIL-SEEDS, ETC. 127 



been made (pp. 49, 50, supra) to Chondrus crispus, 

 Lyngbye,* IRISH MOSS, and Sphczrococcus lichenoides, 

 Ag., CEYLON Moss,f which are used as demulcent 

 foods for invalids. 



Fucus vesiculosus, L., the BLADDER-WRACK, the 

 commonest sea-weed on our coasts, besides being an 

 excellent manure, of use in times of scarcity as a cattle- 

 food, and when burnt into ' kelp/ a main source of 

 iodine, has been employed, when charred, as VEGE- 

 TABLE ETHIOPS, or as a jelly, in scrofulous tumours 

 and glandular enlargements, and is the essential consti- 

 tuent in the remedy for obesity known as * Anti-fat. 'J 



PART III. OIL-YIELDING SEEDS, VEGE- 

 TABLE OIL, AND SUBSTANCES USED IN 

 PERFUMERY. 



THE term ' Oil ' is difficult to define, and the diverse 

 substances included under it are accordingly difficult 

 to classify. Oils may be solid, viscid, limpid or vola- 

 tile, odourless or odorous, and, though consisting 

 mainly of carbon and hydrogen, need not do so exclu- 

 sively. They are mostly insoluble in water, and are 

 all readily inflammable. They may be physically 

 arranged under five groups, so far as they are of 

 vegetable origin : 



i. Non-drying, or greasy fluid oils, 

 ii. Drying oils. 



* Bentley and Trimen, iv, pi. 305. 



t Ibid., iv, pi. 306. % lbid.> iv, pi. 304. 



