326 MATER i A MEDIC A AND THERAPEUTICS. 



Oleum Crotonis PROTON OIL. The oil ex- 

 pressed from the seeds of Croton Tiglium. 



Characters of the seeds. About the size of a grain of coffee, 

 oval or oval oblong, dull brownish- grey, without odour. 



Substance resembling Croton Oil Seed: Castor Oil Seed, 

 which is larger, bright, polished, and marbled. 



Characters of the oil. Slightly viscid ; colour brownish- 

 yellow ; taste acrid ; odour faintly nauseous. 



Composition. The active principle of croton oil is crotonic 

 acid, C 9 H n 2 , a fatty acid, partly free, partly combined with 

 glycerine. With this there are present many fixed oils (oleic, 

 palmitic, stearic, myristic and lauric) as well as their free 

 acids ; and several volatile acids (1 per cent, in all), which give 

 its odour to croton oil, viz. acetic, butyric, baldriac and tiglic 

 acids, and are derived from the fixed oils after extraction only. 



Impurities. Other fixed oils. 



Dose. I to 1 min. placed on the tongue or in crumb of bread. 

 Preparation. 



Linimentum Crotonis. 1 in 8, with Oil of Cajuput. 



ACTION AND USES. 

 1. IMMEDIATE LOCAL ACTION AND USES. 



Externally. Croton oil is a powerful irritant to the skin, 

 causing a burning sensation and redness, followed by a crop of 

 papules, and finally severe pustules, which last for days, heal 

 by scabbing, and may leave unsightly cicatrices. Croton oil 

 liniment is much less used than formerly as a counter-irritant 

 in affections of internal parts, especially the lungs and joints. 



Internally, also, croton oil is a powerful irritant, causing 

 burning in the throat, heat in the epigastrium, possibly nausea, 

 and purgation. It acts as a very rapid drastic cathartic, with 

 some pain, producing a motion within 1 to 2 hours, which 

 is partly solid, the effect being repeated several times during 

 the next twelve hours in a more liquid form. The irritant 

 effect consists chiefly in direct inflammation of the mucous 

 membrane, with increased watery transudation, heightened 

 peristaltic action, probably glandular (not biliary) hyper- 

 secretion. The muscular excitement, and consequent griping 

 which it produces, commence before the oil has reached the 

 duodenum, to be acted on by the pancreatic juice and bile, and 

 are, therefore, partly reflex acts, originating in irritation of the 

 gastric nerves by the free portion of the crotonic acid, section 

 of the vagi postponing its purgative action. This accounts for 

 the rapid action of the drug. 



