Amphitrite

“ The presence of chalk can only be ascertained after separating the lead. This is best done by adding ammonia solution to the nitric acid solution until alkaline, then sulphate of ammonia in excess, and boiling for five minutes. Filter off the black precipitate which is formed, and to the filtrate, first tested with an additional drop or two of sulphate of ammonia to insure the removal of the whole of the lead, add ammoniac oxalate. If a white precipitate appear, it is calcic oxalate. ”

“ Those relating to carbonic acid and ethylene take in the critical point. Others, on hydrogen and nitrogen, for instance, are very extended. Others, again, such as the study of the compressibility of water, have a special interest, on account of the peculiar properties of this substance. M. Amagat, by a very concise discussion of the experiments, has also been able to definitely establish the laws of compressibility and dilatation of fluids under constant pressure, and to determine the value of the various coefficients as well as their variations. ”

“ A common mineral embracing many varieties varying in color and in composition. It occurs in monoclinic crystals; also massive, generally with fibrous or columnar structure. The color varies from white to gray, green, brown, and black. It is a silicate of magnetism and calcium, with usually aluminium and iron. Some common varieties are tremolite, actinolite, asbestus, edenite, hornblende (the last name being also used as a general term for the whole species) . Amphibole is a constituent of many crystalline rocks, as syenite, diorite, most varieties of trachyte, etc. See Hornblende. ”

“ Nitre might be employed, but another well-known substance enables me to make the experiment in a better form. The substance is common sal-ammoniac, or chloride of ammonium, dissolved in water. Cleansing perfectly a glass plate, the solution of the chloride is poured over the glass, to [Pg 101] which when the plate is set on edge, a thin film of the liquid adheres. Warming the glass slightly, evaporation is promoted, but by evaporation the water only is removed. The plate is then placed in a solar microscope, and an image of the film is thrown upon a white screen. ”

“ Then pour finely-divided metallic antimony into a tall jar containing chlorine; the metal instantly ignites, and falls to the bottom as a fiery shower; yet the nature of the chemical action in both these experiments is the same. Make a piece of thick iron wire white hot, and insert it in a large tube containing vapour of sulphur, made by boiling some brimstone in the bottom of the tube; the white-hot iron will catch fire, and burn away like wax, and with intense brilliancy, in the sulphur vapour. ”

“ Thus closely do the absorptions in the two cases run together—thus emphatically do the molecules assert their individuality. As long as their number is unaltered, their action on radiant heat is unchanged. Passing from the lime light to the incandescent spiral, the absorptions of the smaller equivalent quantities, in the two tubes, were 23.5 and 23.4 per cent.; while the absorptions of the larger equivalent quantities were 32.1 and 32.6 per cent., respectively. This constancy of absorption, when the density of a gas or vapor is varied, I have called "the conservation of molecular action." ”

“ Crystals brilliant, transparent, colourless, right rhombic prisms; neutral to test-paper; non-basic; having a faint, cooling, and scarcely nauseous taste; scarcely soluble in cold water; freely soluble in hot water; insoluble in strong alcohol and ether; solution unaffected by alkaline sulphurets, oxalate of ammonia, acetate of lead, or infusion of galls; triturated with quick-lime, ammonia is evolved; heated to 212° Fahr. the crystals lose two equiv. ”

“ I have many times observed how quickly, and, indeed, almost instantaneously, small animals recover from the stupor occasioned by certain permanent gases which are sparingly soluble in watery fluids, as olefiant gas, carbonic oxide and carbonic acid gases, nitrous oxide and the gaseous oxide of methyle. Now amylene is so volatile as to approach to a permanent gas; at a temperature a little above that of the human body it would be a gas, and the vapour is very sparingly soluble in watery fluids, and consequently in the blood. Sulphuric ether is, indeed, as volatile as amylene. ”

“ The ammonia dissolves the dark matter without attacking the silica. The ammoniacal solution is displaced by treating the mass with pure water, or water to which some ammonia has been added, and the whole of the dark matter is thus obtained in a volume of twenty to fifty cubic centimeters of filtrate. The filtrate is evaporated to dryness in a weighed platinum dish, and the weight of residue is determined and the percentage of matière noire calculated therefrom. The residue is incinerated, and when in sufficient quantity the phosphoric acid is determined in the ash. ”

“ Water may be made to absorb more than 1,000 times its volume of ammonia, and more than 500 times its volume of hydrochloric - 355 - acid. Alcohol may absorb more than 300 times its volume of sulphurous acid. Charcoal may absorb 100 times its volume of ammonia, 85 times its volume of hydrochloric acid, 65 times its volume of sulphuretted hydrogen, 55 times its volume of sulphurous acid, and 35 times its volume of carbonic acid. Platinum-black absorbs many times its volume of oxygen and other gases. ”

“ Such salts as are sublimeable crystallize not only in the aqueous way by solution and evaporation, but also by sublimation; and the difference betwixt the figures of these crystals is often very remarkable. Thus, sal ammoniac, by sublimation never exhibits any appearance of feathery crystals, but always forms cubes or parallelopipeds. ”

“ The nitrates decompose in order of the basicities of the metals, and after a short fusion the residue is extracted with boiling water, and the basic salt which separates when the solution is cooled is filtered off. This'contains the most negative metal; and the filtrate, after evaporation and a repetition of the fusion and extraction, may be caused to yield the other oxides. A second method, based on the same principle, consists in the fractional precipitation by some base, such as ammonia, soda, potash, aniline, &c. ”

“ The solution of acetate of ammonia may be recovered from [232] the white lead, and be repeatedly used, for the conversion of further quantities of oxide of lead into hydrate and acetate of lead, which hydrate and acetate are converted into carbonate of lead by the injection of carbonic acid. Theoretically, a given weight of acetate of ammonia in solution, used in conjunction with carbonic acid, should be capable of converting an unlimited quantity of oxide of lead into carbonate of lead ”

“ Both metallic lead and its oxides are soluble in nitric acid, furnishing a solution which may be examined with ease.
Solution of lead salts may be recognised by the following reactions:—Sulphuretted hydrogen, sulphydrate of ammonium, and the alkaline sulphides, give black precipitates, insoluble in the cold dilute acids, alkalies, alkaline sulphides, and cyanide of potassium. Potassium and sodium hydrates give a white precipitate, soluble in excess. Ammonia (except with the acetate) gives a white precipitate, insoluble in excess. ”

“ Many amalgams are formed by the direct contact of a metal with mercury, sometimes with absorption, sometimes with evolution, of heat. Other methods are to place the metal and mercury together in dilute acid, to add mercury to the solution of a metallic salt, to place a metal in a solution of mercuric nitrate, or to electrolyse a metallic salt using mercury as the negative electrode. Some amalgams are liquids, especially when containing a large proportion of mercury; others assume a crystalline form. ”

“ When white light is passed through some transparent solids or liquids and then through a prism, it is found that whole regions of the spectrum are absent. Thus a potassium permanganate solution {35} which is not too concentrated absorbs the whole of the middle part of the spectrum, allowing the red and blue rays to pass through. Since with solids and liquids the absorbed regions are large and somewhat ill-defined, the absorption spectra are not of any great use in the detection of substances. ”

“ With regard to the well-known statement that solids and liquids give continuous spectra, while gases give line-spectra, it must be remarked that metallic vapors show in nearly all cases a continuous spectrum before they condense. Oxygen gives a continuous spectrum at the lowest temperature at which it is luminous. Examining liquids and solids by the method of absorption, we find that many of them show discontinuous spectra, presenting fairly narrow bands. It is not denied that the nearness of molecules does not affect the spectrum. ”

“ To precipitate in succession from a known quantity of the water, the iron by prussiat of potash—the lime by oxalat of ammonia—the alumine and magnesia by caustic potash, which, by boiling, re-dissolves the alumine and leaves the magnesia untouched.
2d method. To precipitate the iron and earths by subcarbonat of ammonia. To evaporate the remaining clear solution to dryness, and apply a red heat. To re-dissolve this saline residue, and evaporate the solution slowly, in order to discover any fixed alkaline sulphat or muriat which may exist in the water. ”

“ Before we venture, however, to entertain any opinions so extravagant in their nature, and so wholly unsupported by analogy, it would be well to enquire how far the change, which ammonia and mercury undergo by Voltaic action, really merits the name of amalgamation. Several chemists of the present day are inclined to refer this change of form to a purely mechanical cause, by which the particles of the metal become separated, and converted, as it were, into a kind of froth by the operation. ”

“ Those substances which have received their chief growth from moisture, whether aqueous or fatty, or have taken on their form by a simpler compacting from them, or have been compacted from these same materials in long ages, if they have a sufficiently firm hardness, if rubbed after they have been polished and when they remain bright with the friction—towards those substances everything, if presented to them in the air, turns, if its too heavy weight does not prevent it. For amber has been compacted of moisture, and jet also. Lucid gems are made of water ”

“ Geoffroy's Table of Affinities; in which the Acid of Sea-salt is marked as having a greater affinity than any other Acid with Metallic substances.
Our solution of Lead is also precipitated in a white powder by several Neutral Salts; such as Vitriolated Tartar, Alum, and common Vitriol. It is by the means of double affinities that these Neutral Salts effect this precipitation.
Even pure water alone is capable of precipitating the Lead of our solution, by weakening the Acid, and thereby disabling it from keeping the metal suspended. ”

“ A vacuum is produced in this reservoir by the use of an air pump, while the acid is being constantly stirred. Lessening of the atmospheric pressure upon water causes its evaporation, and as the vapour is quietly absorbed by the sulphuric acid the water is quickly congealed. It is known that ammonia can be condensed into liquid form by pressure or cold, and is absorbed by and soluble in water to an extraordinary degree. A generator containing a strong so [Pg 215] lution of ammonia is connected by a pipe to an empty receiver immersed in cold water. ”

“ If a solution of a silver salt be precipitated by sodium hydroxide, and aqueous ammonia is added drop by drop until the precipitate is completely dissolved, the liquid when evaporated deposits a violet mass of crystalline silver oxide. If moist silver oxide be left in a strong solution of ammonia it gives a black mass, which easily decomposes with a loud explosion, especially when struck. ”

“ I find that taking ammonium as the basis of hydrogen, according to the ideas which I stated, all the compounds will agree with the suppositions that I mentioned to you, viz. eight cubic inches of hydrogen, two of oxygen, ammonia; four and two, water; four and four, nitrogen; four and six, nitrous oxide; four and eight, nitrous gas; four and ten, nitric acid. Where the multiples are not in geometrical 320 order, the decomposition is most easy, i.e. in nitrous oxide and nitric acid; more easy in water than in ammonia ”

“ This explains why salts are usually inactive and neutral in character, while acids and bases are active agents. Thus we see why the most positive or the most negative elements in general have the strongest affinities, while those intermediate in the list are inactive, and have weak affinities; why alloys of the metals are weak compounds; why a neutral substance, like water, has such a weak affinity for the salts which it holds in solution; and why an aqueous solution is regarded as a mechanical mixture rather than a chemical compound. ”

“ But the long series of reactions, represented by the deportment of nitrite of amyl vapor, does not favor this conception; for, were the atoms animated solely by a common motion, the molecules would not be decomposed. The fact of decomposition, then, goes to prove the atoms to be the seat of the absorption. They, in great part, take up the energy of the ether-waves, whereby their union is severed, and the building materials of the molecules are scattered abroad. ”