Introduction to the study of inorganic chemistry / by William Allen Miller.

  • Miller, William Allen, 1817-1870.
Date:
1871
Catalogue details

Licence: Public Domain Mark

Credit: Introduction to the study of inorganic chemistry / by William Allen Miller. Source: Wellcome Collection.

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    the mouth and throat. Some of its salts, such as corrosive sublimate, wlieii swallowed, act as immediate and j)owerful irritants, ])rodiicing speedy death. Mercury is largely used in j)hiloso])hical enquiries. Its e.xpansion in glass is employed as a measure of temperature in the thermometer ; and it is not only a recjuisite in the construction of the barometer, but it furnishes an indispen- sable li(piid in the ap|)aratus u.sed for the accurate collection and measurement of gases. Mercury forms two o.xides: the grey or black o,\ide (Hg,(J), and the red o.xide (HgO) : both of them yield .salts when treated with acid.s. Mercurous Oxide (Hg.O) is a j)Owerful b.ise, but is unstable when i.solated. Exposure to light or to a moderate heat causes it to sejiarate into the metal and the reil oxi 'e, 1 lg;( )becoming Hg -t- llgO. It is best obtained by grinding calomel with caustic soda in excess, and washing out the sodic chloride — sHgCl -f- aXallO = -f aXaCl -|- H-O. Mercuric Oxide., or the red rrxide (MgO), is olrtained slowly, in red scales, by healing mercury to 300° or 400° in an open flask with a long neck for some days ; but it is more c(mveniently |>rocured by healing the nitrate cautiously till it is enm erted into a bright scarlet |U)wder. It may also be ])recipitated as a yellow ]iowder by adding a solution of potash or soda to one of corrosive sublimate. The red oxide, when healed, becomes black ; and at a higher temperature is se])arated into metallic meia ury and oxygen It is easily dissolved by acids. Mercury forms two sulphides, Hg.S and 1 IgS, the latter, eiu/Kiixir, constituting the ])rinci)>al ore of the metal. It is formed artificially by subliming mercury with about a sixth of its weight of sulphur, when it furnishes the beautiful red jiigment known as 'wruiihou. 'I his suljihideis also obtained as a black iirecipitate by decmniiosing a soluble mercurie salt with sulphuR'tled hydrogen in excess.