John Call Dalton

“ The tenacity of brass is greater than that of either copper or zinc according to Muschenbroek. His experiments give brass nearly twice as strong as copper, and 18 times as strong as zinc. It seems to me most probable that the tenacity of brass increases with the increase of zinc in the alloy to a certain proportion, when it becomes a maximum, and thence diminishes with the further increase of zinc, but experiments are yet wanting, I presume, to ascertain what proportion of the two metals must be taken to form the alloy of greatest tenacity. ”

“ On considering all the circumstances, I am inclined to believe, that the properties which distinguish steel from iron are rather owing to a peculiar crystallization or arrangement of the ultimate particles of iron, than to their combination with carbone or any other substance. In all cases where steel is formed, the mass is brought into a liquid form, or nearly approaching to it, a circumstance which allows the particles to be subject to the law of crystallization. ”

“ Gay Lussac and Thenard find a suboxide of sodium in the same way as that of potassium, and it is probably a compound of soda and sodium: the remarkable oxidation which produces soda is, I should imagine, the protoxide or one atom to one, as obtained by placing sodium in contact with water. A higher oxide is obtained as with potassium, by burning sodium in oxygen gas with a vivid heat. It resembles the yellow oxide of potassium in its appearance and properties. The degree of oxidation varies in the different experiments from 11⁄4 to 13⁄4 times the oxygen of soda. ”

“ The greatest possible quantity of heat which a given weight of elastic fluid can contain is when the dilatation of the fluid is extreme. For, condensation, whether arising from mechanical pressure or from increased attraction of the atoms of matter for each other, tends to dissipate the heat, by increasing its elasticity. Hence increase of temperature, at the same time that on one account it increases the absolute quantity of heat in an elastic fluid, diminishes the quantity on another account by an increase of pressure, if the fluid be not suffered to dilate. ”

“ From the foregoing detail of experiments on elastic fluids, it appears evident that such fluids exhibit matter under a form in which it has the greatest possible capacity for heat, when capacity is understood to denote the total quantity of heat connected with the fluid; but if the capacity or specific heat is meant to denote the quantity of heat necessary to raise the body a given number of degrees of temperature, then the elastic fluid form of matter is that which has the least capacity for heat of any known form of the same matter. ”

“ Now if we assume the atom of vapour to be nearly of the same volume as that of hydrogen, and to consist of 1 atom hydrogen, 2 sulphur, and 1 carbon, it will require 7 atoms of oxygen to form water, sulphurous acid, and carbonic acid, which will accord very well with my experience. When vapourized hydrogen gas is electrified for some time, there is no change of volume, though there is some appearance of decomposition. ”

“ No phosphuretted hydrogen that is not 70 or 80 per cent. pure, can, I imagine, be exploded by nitrous gas; even the purest requires sometimes more than one spark, when mixed in the most favourable proportions; and I have known instances in which the mixture has exploded after electrification for a few minutes. An excess or defect of nitrous gas, occasions oxygen or hydrogen to be found in the residual gas, just as when we explode with oxygen. One volume of phosphuretted hydrogen requires, as nearly as I can find, 31⁄2 of nitrous gas for mutual saturation. ”

“ Various modifications of the proportions of metals and oxygen arise from the combinations of the oxides themselves one with another and with oxygen, so as to lead some to imagine that an atom of metal in some instances combines with 3, 4, or more of oxygen. ”

“ The mixtures of lead, tin, bismuth and other soft and easily fused metals, are still more remarkable in this respect. They should be fused under a cover of oil or tallow in order to keep them of the same [Pg 222] proportions; otherwise, some of them, particularly the tin, is liable to great oxidation, and no two successive fusions will present the same alloy. Hence in some degree the use of fluxes in metallurgy which serve to cover the surface of the metals and prevent oxidation from the atmosphere.
When an alloy is made, it seldom happens that the metal is perfect and compact the first fusion ”

“ I have made many experiments occasionally since 1805, on the quantities of oxygen absorbed and sulphur deposited by quadrisulphuret of lime. They all concur in establishing the same conclusion; namely, that each atom of the compound takes 2 of oxygen and deposits 2 of sulphur, in its transformation from the yellow to the colourless state. For instance, 100 measures of the above 1.056 took 900 of oxygen gas = 1.22 grains, and let fall 2 grains of sulphur, besides a small portion which adhered to the bottle, which was estimated at a few tenths of a grain. ”

“ By means of a neutral solution of nitrate of lead it may be found that 1000 lime water in volume, require about 600 sulphuretted hydrogen, because then a mutual saturation is observed by double affinity; that is, sulphuret of lead and neutral nitrate of lime are formed; but otherwise the liquid remaining is either acid or alkaline. Hydrosulphuret of lime, as well as the other hydrosulphurets, has a peculiar bitter taste. It forms a useful reagent in regard to metals, but is apt to be spoiled by keeping, owing to the acquisition of oxygen. ”

“ Silver and mercury have a considerable affinity and are easily combined by putting lamina of silver into heated mercury and agitating the mixture. When 1 part silver and 2 mercury are mixed as above, a fluid mass is obtained which being heated to the temperature of boiling mercury, a little mercury evaporates and the remainder crystallizes into a soft white mass, which in time grows [Pg 232] hard and brittle. A higher heat than boiling mercury expels the mercury. Hence this amalgam may be used for giving a thin coating of silver to the surface of metals, like that of gold. ”

“ Thinking it might in part be owing to the iron, I transferred the acid to soda, by decomposing the nitrate of iron by the carbonate of soda; this nitrate of soda however, when treated with oxymuriate of lime, exhibited the same phenomenon as the nitrate of iron. When an acid is added the oxymuriatic acid itself is given out. These results will require further consideration. At present I am inclined to think the pungent gas is one atom of nitrous and one of oxygen or what I formerly considered as nitric acid. ”

“ Sulphur and arsenic are found native in certain places, combined in masses of a brownish red or orange colour and glassy fracture: this combination is called realgar, and is also manufactured in large quantities in Saxony, chiefly for the use of calico-printers. Its constitution and specific gravity vary considerably, owing chiefly I imagine to the greater or less heat to which it is exposed, and to the proportions of the elements in the first mixture. I have specimens of 3.3 and 3.7 sp. gr.; and it is probable these are not the extremes; the heaviest is the darkest colour. ”

“ The protoxide is blue when precipitated, but it is supposed to contain water, or to be a hydrate; as it is dark grey when heated. The blue oxide in a short time after precipitation being still under water, changes to a yellowish or dead-leaf colour; which also appears to be a hydrate of the protoxide, as it dissolves in acids without giving out gas, and yields the blue oxide by an alkali. ”

“ Cast iron or crude iron is the metal when first extracted from the ore; it usually contains carbone, oxygen, phosphorus and silica, in small proportions, with perhaps other earths occasionally. It cannot be considered as having these elements united in definite proportions; for they vary much, and probably give to crude iron its several modifications. Cast iron contains about 80 per cent. of its weight of iron in a state capable of solution in dilute sulphuric acid, and yielding a corresponding quantity of hydrogen gas. ”

“ Oxide of Palladium.
The discoverer of this metal, Dr. Wollaston, has given us its distinguishing chemical properties; but we are indebted to Berzelius and Vauquelin for the proportions of oxygen and sulphur which combine with the metal (Vid. Annal. de Chimie, 77 and 78.) Few chemists have had an opportunity of making experiments on this metal, owing to its great scarcity and the consequent high price of it (1 shilling per grain) . It does not seem desireable that any but those skilled in the more delicate chemical manipulations should operate upon articles such as the present. ”

“ Gold does not burn by exposure to heat, but gold leaf and gold wire may be deflagrated by electricity and galvanism; a purple powder is the product, which is considered by some as the protoxide of gold; but others, after Macquer and Proust, conceive with greater probability that this powder is nothing but gold reduced to its ultimate division. Solutions of gold which are of a fine yellow, give a purple stain; and gold deoxidized by green sulphate of iron is precipitated blue, which precipitate gradually assumes a yellow colour as the particles become [Pg 6] united. ”

“ There appear to be two nitrous acids; namely, the one which I have designated by that name, which may now be called subnitrous, or as Gay Lussac terms it pernitrous; and the other what I considered as nitric acid in the former volume, composed of 1 atom azote, and 2 of oxygen.
Real nitric acid then is that combination which is effected by uniting oxygen with a minimum of nitrous gas; or 1 measure of oxygen with 1.3 nitrous gas, (See Vol. 1, page 328) . The oxynitric acid, which I was led to infer from the last mentioned combination, (1 azote with 3 oxygen) does not appear to exist. ”

“ The object being to deoxidize indigo and obtain it in solution in a green state, we may suppose that 1 atom arsenic takes the oxygen from the indigo and then forms arseniate of lime which precipitates, whilst the other atom in union with the sulphur, takes the green indigo and unites it to the potash, making a quadruple compound of arsenic, sulphur, green indigo and potash in solution. ”

“ The green oxide being the most prominent compound next to the chromic acid, being commonly produced from it by any deoxidizing process, being the lowest oxide known, and combining with acids, is on these accounts entitled to the consideration of the protoxide; indeed there does not seem an instance where the protoxide of a metal is unknown, whilst the deutoxide and compound oxides are known. ”

“ Sulphur may be combined with the earths, alkalies and metals, by heat, of various degrees according to the nature of the subjects. The union is attended in many cases with a glowing ignition, indicating the evolution of heat. The metallic oxides and sulphur when heated together commonly produce a sulphuret of the metal, whilst the oxygen escapes with part of the redundant sulphur in the form of sulphurous acid, and the rest of the sulphur sublimes. ”

“ When pure green sulphate of iron is dropped into water and then the oxide precipitated by a gradual addition of lime water, it falls down yellow in proportion to the oxygen in the water, which may be increased 3 or 4 times by artificial impregnation. If the oxygen of the water be previously saturated with nitrous gas, then the oxide is wholly precipitated green. ”

“ When 10 parts nitrous oxide and 5 of ammonia are exploded over mercury, the residuary gas contains some free oxygen and some nitrous acid derived from the decomposition of the excess of nitrous oxide used; with 6 parts of ammonia there is rarely any free oxygen. When 10 parts of nitrous oxide, and 7 of ammonia are fired, I never found any free oxygen or hydrogen ”