Microscopic Structure—The testa is chiefly formed of cylindrical thick-walled cells. The albumen exhibits large angular cells containing fatty oil, masses of albuminous matter and tufted crystals of calcium oxalate. Starch is not present.
Chemical Composition—The kernels afforded us by means of ether 51·5 per cent. of fatty oil, which is almost colourless or somewhat brownish if the seeds are not fresh. Either extracted or expressed it is of no peculiar taste. The pressed oil concretes at 17° C.; that extracted by ether or bisulphide of carbon requires for solidification a lower temperature. The expressed oil is slightly fluorescent, less so that extracted by means of bisulphide of carbon. If the oil, either pressed or extracted, is diluted with the bisulphide, and then concentrated sulphuric or nitric acid is added, no peculiar coloration is produced.
From the powdered kernels deprived of oil, water removes the usual constituents, glucose, mucilage and albumin.
Uses—The seeds are said to have been advantageously used as an alternative tonic in scrofula, skin diseases and rheumatism. They should be freed from the testa, powdered, and given in the dose of 6 grains gradually increased. Reduced to a paste and mixed with Simple Ointment, they constitute the Unguentum Gynocardiæ of the Indian Pharmacopœia, which, as well as an expressed oil of the seeds may be employed externally in herpes, tinea, &c.[323]
Substitute—It has been suggested that the seeds of Hydnocarpus Wightiana Bl., a tree of Western India, and of H. venenata Gärtn., native of Ceylon, might be tried where those of Gynocardia are not procurable. The seeds of both species of Hydnocarpus (formerly confounded together as H. inebrians Vahl) afford a fatty oil which the natives use in cutaneous diseases.[324]
POLYGALEÆ.
RADIX SENEGÆ.
Radix Senekæ; Senega or Seneka Root; F. Racine de Polygala de Virginie; G. Senegawurzel.
Botanical Origin—Polygala Senega L., a perennial plant with slender ascending stems 6 to 12 inches high, and spikes of dull white flowers resembling in form those of the Common Milkwort of Britain. It is found in British America as far north as the river Saskatchewan, and in the United States from New England to Wisconsin, Kentucky, Tennessee, Virginia and the upper parts of North Carolina, as well as in Georgia and Texas, not in the Rocky Mountains.
The plant, which frequents rocky open woods and plains, has become somewhat scarce in the Atlantic states, and as a drug is now chiefly collected in the west, the plant growing profusely in Iowa and Minnesota, west of New York.