Active Ingredients. - The only portion of senega employed in medicine is the root, which, although nearly inodorous, possesses a peculiar, bitter, and pungent flavor. If chewed, it leaves a sensation of acrimony, which is deepened if the saliva be swallowed. The interior is nearly or quite inert, the virtues residing exclusively in the bark. These are brought out by water, but more completely by spirit; but it is said that neither the decoction nor the infusion possesses value equal to that of the simple powdered root. The most important ingredient is the alkaloid polygaline or senegine, called also saponine, struthiine, quillagiue, githagine, monninine, and monesine, according to the source whence de rived, since it is present in many different plants. This alkaloid is an amorphous white powder, neutral and odorless, but capable of exciting severe sneezing if smelt; the taste is sweet at first, but has a secondary sharpness and pungency. Senegine is freely soluble in water, very little soluble in cold strong spirit, and not at all soluble in ether. Concentrated sulphuric acid dissolves it with a reddish-yellow color, that changes to bright red. The watery solution is peculiar, from its lathering like soapsuds.

There is probably a second active ingredient in senega, specially soluble in alcohol, and which does not exist to any large extent in infusions or decoctions.

Physiological Action. - The action of senegine, and the similar substances extracted from other plants, has been carefully studied by a number of experimenters. Schroff1 found that in man, in doses of 1/3 grain to 3 grains, it produced a certain amount of nausea, with a bitter taste and prickling in the mouth. From 2 1/2 to 3 grains also produced irritative cough, and secretion of mucus, lasting for several hours, in the bronchial tubes, but no effect was manifested upon either the kidneys or the skin. Applied locally to any breach of skin or mucous membrane, senegine and the kindred substances (especially monesine) produce severe pain and irritation, followed by ulcers which give out a plastic exudation, and become covered with a more or less gray-colored membrane.

There is ample proof, however, that senegine is, in large quantities, a poison to the voluntary muscles; in this respect githagine, and one or two of the other representatives, are more powerful even than senegine itself.

Therapeutic Action. - The earliest use of senega appears to have been with a tribe of North American Indians called Senegaroos, who esteemed it an antidote to the bite of the rattlesnake. They applied it both externally and internally.

Whether superior, as a specific, to many other plants which are similarly employed, appears still to be unsettled. That it is beneficial in cases of pneumonia and other chest affections appears to be well established. In the advanced stages of pneumonia, when the cough is obstinately dry, irritating, and painful, with a sense of tightness and oppression across the chest, and when other remedies, in appearance more markedly indicated, have failed to give relief, I have found this medicine remove the tightness and oppression, relieve the cough, and rapidly promote expectoration.

In the bronchitis of old people, and especially when complicated with emphysema, where the cough is harsh, dry, and irritating, the breathing oppressed, and pains are felt more or less throughout the chest, senega will often act more beneficially than any other drug.

I have also employed it in humoral asthma with much success. It not only diminishes the secretion, but promotes easy expectoration and relieves the oppression. In such cases it has been highly commended by many physicians. The American Dr. Archer introduced it as a remedy of great power in croup; while Dr. Barton and many other celebrated American practitioners regarded it as a valuable auxiliary to medicines ordinarily employed in this disease. It is very desirable that experimental inquiries should be instituted in regard to the action of this drug in croup. It is sometimes used also in whooping-cough.

1 Lehrbuch der Pharmakologie.

Dr. Percival and others have praised senega as a diuretic that may be usefully employed in dropsies dependent upon kidney disease; but many recent writers have denied its action on the kidneys or skin. It unquestionably exerts a powerful influence on the nervous system, somewhat resembling that of arnica.

Senega-root has further been employed with advantage in amenor-rhoea, a saturated decoction being given to the extent of a pint in twenty-four hours, during the fortnight preceding the monthly function. On the other hand, it is interesting to note that senegine (or rather monesine) has been successfully employed by Martin St. Ange, in 2-grain doses, as a remedy for uterine haemorrhage.

Lastly, it is said that in consequence of its stimulant and diaphoretic effects, senega has proved itself a powerful help in the treatment of chronic rheumatism and rheumatic paralysis.

Preparations and Dose. - Extractum Senegas, gr. i. - v. (.06

- .30). Syrupus Senegae, 3 i. - ij. (5. - 10.). Decoctum Senegae, 3 ss. - i (15. - 30.)