Mercury(II) oxide

“ Mercury oxide does not contain two simple bodies, a gas and a metal, but two elements, mercury and oxygen, which, when free, are a gas and a metal. Neither mercury as a metal nor oxygen as a gas is contained in mercury oxide ”

“ As many of the compounds of mercury decompose on being heated—for instance, the oxide or carbonate [17] —and as zinc, cadmium, copper, iron, and other metals separate mercury from its salts, [18] it is evident [51] that mercury has less chemical energy than the metals already described, even than zinc and cadmium. Nitric acid, when acting on an excess of mercury at the ordinary temperature, gives mercurous nitrate, HgNO3. ”

“ Mercury, within a certain range of temperatures situated close to its boiling point, combines slowly with oxygen into the red oxide, which, however, breaks up again at higher temperatures. All other metals, when heated in oxygen or air, are converted, more or less readily, into stable oxides. ”

“ Oxygen.—Mercury and copper and some other metals are capable of dissolving their own oxides. Mercury, by doing so, becomes viscid and unfit for its ordinary applications. Copper, when pure to start with, suffers considerable deterioration in plasticity. But the presence of moderate proportions of cuprous oxide has been found to correct the evil influence of small contaminations by arsenic, antimony, lead and other foreign metals. ”

“ The precipitate (oxide of mercury) is then caught on a filter, washed, and dried. Thirty grains of this powder, mixed with four or five grains of sulphur, and struck with a heavy hammer, or heated on an iron, will explode with violence. The oxide of mercury, obtained from its solution by lime-water, has the same effect, when treated in the same manner. Another process recommended is, to precipitate a solution of the perchloride of mercury (corrosive sublimate) by lime-water, and treat the precipitate with sulphur, as above described. ”

“ Grey oxide of mercury, 20 gr.; lard, 1 oz.; mix, and expose them to the temperature of 320° Fahr. for 2 hours, constantly stirring. Grey coloured. It may also be made from the nitric- or red-oxide in the same way, by keeping the ointment heated to about 300° for some hours. Cleaner and stronger than Ung. hyd. fort.—Ph. L.
3. (Tyson.) Black oxide of mercury (prepared by decomposing precipitated calomel with liquors of potassa and ammonia) , 2 oz.; lard, 1 lb.; triturate together. Inferior in activity to the last. It closely resembles in appearance a fine sample of mercurial ointment. ”

“ Mercury occurs in nature chiefly as the sulphide (HgS) called cinnabar, and in globules of metal inclosed in the cinnabar. The mercury mines of Spain have long been famous, California being the next largest producer.
Metallurgy. Mercury is a volatile metal which has but little affinity for oxygen. Sulphur, on the other hand, readily combines with oxygen. These facts make the metallurgy of mercury very simple. The crushed ore, mixed with a small amount of carbon to reduce any oxide or sulphate that might be formed, is roasted in a current of air. ”

“ Or again, if a mercury surface be simply touched with a pin, the slight sparking that is produced on making the current will soon form a little pile of dirty oxide at the point of entry, and the contact will frequently fail. If it be necessary to have a mercury contact, the pin must be well driven in below the surface of the mercury or else swept through it as an oar is swept through the water. Another form of electrical contact that acts well is a knife edge brought into contact with a series of fine elastic strips of metal laid parallel to one another like the fingers of a hand. ”

“ Agitate the crude oil of bitter almonds with mercuric oxide in slight excess, and, after a few days’ contact, rectify the oil from a little fresh oxide. The product is quite pure when the process is properly managed. The bicyanide of mercury thus formed may be either employed as such, or reconverted into oxide of mercury and hydrocyanic acid. ”

“ The amount of mercury which combines with 16 parts by weight of oxygen is easily found by heating a weighed quantity of oxide of mercury, as Priestley and Scheele did, and weighing the residue of metal. The results of the most accurate experiments show that 200·36 grams of mercury combine with 16 grams of oxygen, and if the compound consists of one atom of each element, 200·36 must be the atomic weight of mercury. The first idea which naturally occurs is to find out the relative weight of mercury gas. ”

“ The proportions of metal and oxygen in the two oxides may be found by precipitating a known weight of mercury reduced by solution to either of the oxides, then drying and weighing the oxides, when the increase of weight by the addition of oxygen may be observed. This method is less accurate with regard to mercury than to other metals, on account of the very great weight of the atom, by which a small error in the gross weight of the oxide will be a great one as it respects the oxygen. ”

“ The heat of a sand bath is employed. 120 lbs. of mercury, and 48 lbs. of nitric acid (sp. gr. 1·48) yields 112 lbs. of red precipitate. (Brande.)
Uses, &c. Red oxide of mercury, whether obtained by calcination or precipitation, possesses the same general properties. It is very slightly soluble in water, but sufficiently so to give that fluid an alkaline reaction, and a metallic taste. It was formerly employed in medicine to induce salivation; but is now chiefly used as an escharotic, either in the form of powder or made into an ointment.—Dose, 1⁄8 to 1 gr., combined with opium. ”

“ Most mercurous salts are insoluble in water, the principal soluble one being the nitrate, which is made by the action of cold, dilute nitric acid on mercury.
Mercuric chloride (corrosive sublimate) (HgCl2) . This substance can be made by dissolving mercuric oxide in hydrochloric acid. On a commercial scale it is made by subliming a mixture of common salt and mercuric sulphate:
2NaCl + HgSO4 = HgCl2 + Na2SO4. ”

“ The black films of tin, lead and cadmium dissolve at once in the acid, the lead film being also soluble in bleaching-powder. The oxide films of antimony, arsenic, tin and bismuth are white, that of bismuth slightly yellowish; lead yields a very pale yellow film, and cadmium a brown one; mercury yields no oxide film. The oxide films (the metallic one in the case of mercury) are tested with hydriodic acid, and with ammonium sulphide, and from the changes produced the film can be determined (see F.M. Perkin, Qualitative Chemical Analysis, 1905) . ”

“ In order to dry a salt it must be heated at about 100° until its weight remains constant, or be placed under an air pump over sulphuric acid, as will also be presently described. As water is met with almost everywhere, and as it is absorbed by many substances, the possibility of its presence should never be lost sight of.
[18] As the decomposition of red oxide of mercury requires so high a temperature, near redness, as to soften ordinary glass, it is necessary for this experiment to take a retort (or test tube) made of hard glass, which is able to stand high temperatures without softening. ”

“ In order, if possible, to procure the amalgams in quantities sufficient for distillation, he combined the 301 methods he had employed in the first instance, with those pursued by Berzelius and Pontin. "A mixture of the earth with red oxide of mercury was placed on a plate of platina, a cavity was made in the upper part of it to receive a globule of mercury, the whole was covered by a film of naphtha, and the plate was made positive, and the mercury negative, by a proper communication with the battery of five hundred." ”

“ In modern times the solidification of mercury had been frequently witnessed by these who dwelt in northern climates and by the skilful use of certain freezing mixtures made up of ordinary salts, it is not difficult to exhibit this metal in the solid state at any time. But it was not until the discovery of the liquefaction of carbonic acid, nitrous oxide, and other gases by Faraday, about 1823, that the freezing of mercury became a common lecture-room experiment. ”

“ Reduce sulphate of mercury, 20 oz., and chloride of sodium, dried, 16 oz., each to fine powder, and having mixed them add black oxide of manganese, in fine powder, 1 oz., thoroughly by trituration in a mortar, place the mixture in an apparatus adapted for sublimation, and apply sufficient heat to cause vapours of perchloride of mercury to rise into the less heated part of the apparatus arranged for their condensation. ”

“ In the preparation of ointment of oleate of mercury it is of the utmost importance that the mercuric oxide should be thoroughly dry, and further that it should be sifted in small portions at a time upon the surface of the oleic acid, each fresh portion being well incorporated before another is added. Solution should be promoted by frequent stirring, at ordinary temperatures, since experience has shown that all heating is positively injurious. ”

“ HgCl2,2HgO (magnesium and zinc form similar compounds) . This compound is obtained by mixing a solution of corrosive sublimate with mercuric oxide or with a solution of sodium bicarbonate. In general, with both mercurous and mercuric salts, there is a marked tendency to form basic salts. [24]
Mercury has a remarkable power of forming very unstable compounds with ammonia, in which the mercury replaces the hydrogen, and, if a mercuric compound be taken, its atom occupies the place of two atoms of the hydrogen in the ammonia. ”

“ We are here presented with a combination of fœtid gums, in which assafœtida is the most potent article. Antispasmodic, and emmenagogue. Dose, grs. x to ℈j. See Form: 10, 27, 98.
Pilulæ Hydrargyri. L.E.D. Pil. Mercuriales. P.L. 1745, vulgo, The Blue Pill. The mercury in this preparation, is not, as it was formerly considered, in a state of mere mechanical division, but in that of a black oxide, upon which its activity as a remedy undoubtedly depends; for mercury in its metallic state is entirely inert with regard to the living system. ”

“ Mercurous salts are generally insoluble, and may be converted into mercuric salts by prolonged boiling with oxidising agents (nitric acid or aqua regia) . The salts of mercury are volatile, and, if heated with a reducing agent or some body capable of fixing the acid, metallic mercury is given off, which may be condensed and collected.
Mercury is separated from its solutions by zinc or copper, or it may be thrown down by stannous chloride, which, when in excess, gives a grey powder of metallic mercury, or, if dilute, a white crystalline precipitate of mercurous chloride. ”

“ Oxidised, or otherwise impure mercury, may adhere to glass; moreover, such mercury would not have the density of the pure metal, and therefore the barometric column would be either greater or less than it should be. The mercury of commerce generally contains lead; sometimes traces of iron and sulphur. It is necessary, therefore, for the manufacturer to purify the mercury; and this is done by washing it with diluted acetic, or sulphuric acid, which dissolves the impurities. No better test can be found for ascertaining if the mercury be pure than that of filling a delicate thermometer tube ”

“ In the liquid state the adhesion of the mercury to the metallic body plunged into it and afterwards withdrawn, varies with the rapidity of the motion and with the purity of the mercury. Frequently—I may say always—the inversion takes place too soon or too late, and thus gives rise to an attraction or repulsion, in a contrary direction to the rotation. Moreover it is very difficult to preserve the mercury pure when in contact with other metals; and even the purest mercury is disposed to oxidize easily under the influence of the electric sparks. ”

“ The non-metallic elements, with the exception of chlorine, oxygen, nitrogen, and carbon, combine directly with it, evolving in most cases both light and heat. It combines with hydrogen, even in the dark, without the addition of any external energy, and converts most metals into their fluorides. Gold and platinum are not attacked in the cold, but when gently heated are easily corroded. Mercury readily dissolves the gas, forming the protochloride; iron wire also completely absorbs the gas, while powdered antimony and lead take fire in it. ”

“ All the metals are fusible, but some require very different degrees of heat to render them fluid,—platinum requiring the heat of the oxy-hydrogen blowpipe, while tin melts in the flame of a candle, and mercury is fluid at all temperatures in this climate, but becomes solid at 40° Fahr. below 0,—a temperature occasionally experienced in the Arctic regions, where the mercurial thermometer is useless, the mercury becoming solid. ”

“ In discussing the pharmacology of mercury and its compounds, it is of the first importance to observe that metallic mercury is inert as such, and that the same may practically be said of mercurous salts generally. Both mercury itself and mercurous salts tend to be converted in the body into mercuric salts, to which the action is due. When metallic mercury is triturated or exposed to air it is partly oxidized, the first stage of its transformation to an active condition being thus reached. ”

“ Yes, like any other liquid; only it requires a much greater degree of heat. At the temperature of six hundred degrees, it begins to boil and evaporate like water.
Mercury combines with gold, silver, tin, and with several other metals; and, if mixed with any of them in a sufficient proportion, it penetrates the solid metal, softens it, loses its own fluidity, and forms an amalgam, which is the name given to the combination of any metal with mercury, forming a substance more or less solid, according as the mercury or the other metal predominates. ”