Characters. - Small, white, crystalline plates, or a crystalline powder, permanent in the air, odourless, having a sweetish saline and mildly alkaline taste and a feebly acid reaction.

Solubility. - Soluble in 1.5 parts of water and in 6 parts of alcohol at 15° C. (59° F.); very soluble in boiling water and in boiling alcohol.

Reactions. - When heated the salt gives off inflammable vapour and leaves an alkaline residue amounting to between 30 and 31 per cent3. of the original weight, and which gives the reactions of sodium carbonate.

Dose. - In rheumatism with high temperature 10 to 20 grains every two to four hours. The addition of some aromatic spirit of ammonia, or alcohol in some form, tends to lessen the cardiac depression which the salicylate alone may cause.

Action and Uses. - It agrees in its action with salicylic acid, excepting that it has no power to destroy low organisms. In febrile conditions, and especially in acute rheumatism, it greatly lowers the temperature and lessens the pain. Its use should be continued for some time after apparent convalescence, as the temperature is apt to rise again when the administration of the remedy ceases. It often gives relief in tonsillitis. In small doses it is useful in chronic rheumatism. In doses of 1/2 to 2 1/2 grains every quarter or half hour it will often cut short headaches. The symptoms of its physiological action are the same as those of salicylic acid (see p. 819) - ringing in the ears, etc. (pp. 228 and 229). These symptoms may be lessened by ergot, hydrobromic acid, or bromides. It renders the bile more watery, and so may be used to prevent gall-stones; it is sometimes very useful in diabetes.

Preparation.

Dose.

Trochisci Sodii Santoninatis .....................................

1 grain in each, 1-5 lozenges.