Unpublished paper, 'On magnesium' by T L [Thomas Lamb] Phipson

Description

Phipson describes a series of experiments, finding that iodine and sulphur can be distilled off magnesium without attacking the metal. Observing the decomposition of silicic acid, heated for some time in a porcelain crucible with excess of anhydrous silica, Phipson notes that the metal burns vividly if the air has access; and a certain quantity of amorphous silicium is immediately formed. Magnesium is therefore capable of reducing silicic acid at a high temperature. The reason why potassium and sodium cannot effect this is simply because these metals are highly volatile and fly off before the crucible has attained the proper temperature. Magnesium being much less volatile than the alkaline metals, takes oxygen from silica before volatilising. If the silicic acid be in excess, a silicate of magnesia is formed at the same time; if the metal is in excess, much siliciuret of magnesium is produced. The presence of the latter is immediately detected by throwing a little of the product into water acidulated with sulphuric acid, when the charac­teristic phosphoric odour of siliciuretted hydrogen is at once perceived.

Annotations in pencil and ink throughout.

Subject: Chemistry

Received 9 March 1864. Read 21 April 1864. Communicated by Professor G G [George Gabriel] Stokes.

Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 13 of the Proceedings of the Royal Society as 'On Magnesium'.

Reference number

AP/46/5

Earliest possible date

1864

Physical description

Ink and graphite pencil on paper

Page extent

7 pages

Format

Manuscript