STANNUM - TIN, SN, = 118 (NOT OFFICINAL).

This metal is known to occur only in the mineral kingdom, and in minute quantity in the water of Sadschiitz.

Characters And Tests

Silver-white in color, with a tinge of yellow, and high metallic lustre, unaffected by moisture or exposure, inelastic, but flexible; when rubbed it imparts to the fingers a peculiar odor. It is a good conductor of heat and electricity, has a sp. gr. of 7.292, melts at 442° F., and at a higher temperature burns with a brilliant white light; at ordinary temperatures it is not brittle, but when heated to near the fusing point may be easily powdered. Nitric acid does not act upon it, except in presence of water; hydrochloric acid dissolves it with evolution of hydrogen.

Solution of chloride of tin, SnCl2 (Appendix, B. P.), absorbs oxygen readily, and hence is a powerful deoxidizing agent. It reduces to the metallic state the salts of mercury, silver, gold, etc., and is made use of for this purpose; also as a test for ammoniated mercury.

Preparations And Dose

Pulvis stanni (not officinal): dose, 20 to 40 gr. as a vermifuge - it may be given in honey or treacle three or four times daily for several days, and should then be followed by a cathartic. Stanni chloridum: dose, 1/16 to 1/2 gr. two or three times daily in pill or in chloric ether - a lotion may be made with 1 gr. to the ounce.

Physiological Action (Internal)

The metal itself is inert, but if taken into the stomach may be so far acted on by acids or saline substances as to be rendered soluble in the form of chloride, and may then produce some irritant effects. The fact of such a change sometimes occurring, and sometimes not, may explain the disagreement between the results of Orfila, who considered oxide of tin to be a poison, and Schu-barth, who considered it inert.

It has been said that fatty, or acid, or simply albuminous articles of food, after having been kept in tinned vessels (free from lead) have sometimes occasioned colic and vomiting, but this must be exceptional. We may note that arsenic is a usual constituent of tin-ores, and in small quantity it is generally present in all tin that has not been carefully purified, and irritant effects may have occurred from it (Gubler).

The chloride, or "butter of tin" is stated to exert a tonic, antispasmodic effect, when given in small quantities, but in large doses it causes muscular twitching, convulsion, and paralysis; also some gastrointestinal irritation, with dryness of mouth and throat.

Therapeutical Action