This section is from the book "A Text Book Of Materia Medica, Being An Account Of The More Important Crude Drugs Of Vegetable And Animal Origin", by Henry G. Greenish. Also available from Amazon: A Text Book of Materia Medica : Being an Account of the More Important Crude Drugs of Vegetable and Animal Origin.
Croton seeds are the seeds of Croton Tiglium, Linne (N.O. Euphorbiaceoe), 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 resembling that of the castor plant, but devoid of spines. The seeds are exported, and the oil pressed from them in this country.
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 opposite extremity. The outer, dull brownish layer is easily removed, disclosing a hard dark coat; in many commercial specimens the friction of the seeds against one another has been sufficient partially to effect this, giving the seeds a mottled appearance.
The kernel is yellowish and oily, and consists of a large endosperm enclosing papery cotyledons and a small radicle.
The taste of the kernel, in ascertaining which great caution is necessary, is at first oily, but this is succeeded by an unpleasant acridity; the seeds have no marked odour.
The student should compare these seeds with castor seeds and observe
(a) The dull brownish outer layer,
(b) The prominent line separating the ventral from the dorsal surface.
The seeds also contain the toxic albumoses croton-globulin and croton-albumin, which together are also known as crotin, and resemble ricin. Croton oil is brownish yellow and slightly fluorescent; it is soluble in less than its own volume of absolute alcohol, but on further addition of alcohol two layers are formed, the active constituent of the oil being contained in the alcoholic layer. The solubility appears to depend on the proportion of free acid present and to increase with the age of the oil. See also ' Croton Oil.'
Croton oil is a powerful irritant, producing, when applied to the skin, a burning sensation and redness, followed by severe pustules; it is used, diluted, as a counter-irritant. Internally it is a very rapid, drastic cathartic, and is given in certain cases of apoplexy.