184 SEEDS 



It is much used for lubricating hot machinery, and for illuminating purposes. 

 See also ' Castor Oil.' 



Ricin is extremely poisonous, O002 of a milligramme per kilo, being fatal 

 to rabbits. It is capable of producing an antitoxin (antiricin) in the body, 

 and it is interesting to note that Ehrlich's researches on this property led to 

 the preparation of antidiphtheritic and other sera (Miiller, 1899). Ricin is 

 probably identical with Bubnow and Dixon's ricinone (Finnemore and Deane, 

 1905) ; its activity is destroyed by heating to 100. It forms with abrin (Abrus 

 precatorius, Linne), crotin (Croton Tiglium, Linne), curcin (Jatropha Curcas, 

 Linne), and two or three others a group of toxins (toxalbumoses, phytalbumoses) 

 possessing similar properties ; being insoluble in oil it is left in the cake when 

 the seeds are pressed and renders the cake unfit for cattle food. 



The lipase in the seeds has been turned to commercial use as a convenient 

 means of splitting oils into glycerin and fat-acids ; any lipase present in the 

 expressed oil is rendered inactive by the steaming. 



Uses. The oil expressed from the seeds is valuable as a simple 

 purgative, at once rapid and certain, mild and painless. On account 

 of their violent action the seeds themselves are never employed in 

 this country, though in some countries they are said to be a favourite 

 purgative. 



Note. Semina Ricini Majores (Physic Nuts, Purging Nuts, Pignons d'Inde) 

 are the seeds of Jairopha Curcas, Linn6 ; they resemble castor seeds in shape, 

 but are rather large, dull black ; surface minutely rugose, with small white 

 patches ; they contain a fixed oil, much more purgative than castor oil, and 

 curcin (see above). 



CROTON SEEDS 



(Semina Crotonis) 



Source, &C. Croton seeds are the seeds of Croton Tiglium, Linne 

 (N.O. Euphorbiacece) , a small tree indigenous to and cultivated in 

 India. They were used medicinally in the seventeenth century, but 

 fell into disuse owing probably to the violence and uncertainty of their 

 action. The oil was introduced from India about 1819, and was found 

 to be, in certain cases, a valuable cathartic. 



The tree produces a three-celled, three-seeded capsular fruit re- 

 sembling that of the castor plant, but devoid of spines. The seeds 

 are exported, and the oil pressed from them in this country. 



Description. Croton seeds are of a dull cinnamon-brown colour 

 and oblong outline ; they are about 12 mm. in length, and resemble 

 castor seeds in size and shape, though they are rather more angular 

 in transverse section, the ventral and dorsal surfaces being separated 

 by a prominent line. The caruncle which the seed possesses is easily 

 detached, and is therefore seldom to be found in the drug ; the hilum 

 is less distinct than in castor seed, and from it the raphe runs along 

 the ventral surface of the seed, terminating in a dark chalaza at the 



