The active principle of elaterium. It may be obtained by exhausting elaterium with chloroform, adding ether to the chloroform solution, collecting the precipitate, washing the latter with ether, and purifying by recrystallisation from chloroform.

Characters. - A chemically neutral substance with a bitter taste. In small colourless crystals.

Solubility. - It is insoluble in water, sparingly soluble in rectified spirit.

Reactions. - When heated it melts and burns without residue. With melted carbolic acid it yields a solution which, on the addition of sulphuric acid, acquires a crimson colour rapidly changing to scarlet. It is not precipitated from solution by tannic acid, nor by the salts of mercury or of platinum.

Dose. - 1/40 to 1/10 gr.

Preparations.

B.P.

Dose.

Pulvis Elaterini Compositus (elaterin, 1; sugar of milk, 39)......

1/2-5 gr.

U.S.P.

Trituratio Elaterini (1 gr. elaterin, 9 gr. sugar of milk..............................................

1/2-3/4 gr.

Action and Uses. - Elaterin is the most powerful hydra-gogue cathartic we possess, increasing the peristaltic action and flow of fluid from the intestines. It only acts as a purgative when taken internally, and appears to require bile in order to act. When injected subcutaneously it acts on the nervous system, causing salivation, insensibility, tetanus, and dyspnoea. It is used in dropsies, especially those affecting the abdominal cavity and due to cirrhosis of the liver. It is also used as a depletory in cerebral affections. It is usually combined with henbane and volatile oils, as it is apt to gripe. In large doses it may cause gastro-enteritis and fatal collapse, and should be given with care to old or feeble persons.