Chemical law

“ To destroy organic matter the most powerful oxidizing agents are required. We must boil it with nitric acid and chloric acid and the most perfect chemical agents. To think to get rid of organic matter by exposure to the air for a short time is absurd. ”

“ The peculiar manner in which hydrogen gas appears to dissolve solid substances,—as iron, potassium, sodium, sulphur, phosphorus, selenium, and arsenic, may be explained by regarding the results as a manifestation of the powers of chemical affinity over the forms of bodies. In like manner, the solution of salt in water, or the mixture of alcohol in that fluid, may be viewed as chemical phenomena, although usually considered as simple cases of solution or mixture: alterations of temperature and other physical changes taking place in either. ”

“ The view long maintained—until late in the nineteenth century, in fact—that organic and inorganic chemistry are separated from each other by a wide gap, is no longer held. Hundreds of organic substances, some of them of great complexity, have been made in the chemist’s laboratory, and can now be classed as properly with inorganic as with organic substances. The gap has been closed, and there is now but one chemistry. Only the most intricate chemical compounds still lie beyond the chemist’s grasp, and the isolation of these may be at any time overthrown. ”

“ When oxygen combines with a single element, what is the compound called? We have found that O makes up a certain portion of the air; later, we shall see how large the proportion is. Its tendency to combine with almost everything is a reason for the decay, rust, and oxidation of so many substances, and for conflagrations, great and small. New compounds are thusformed, of which O constitutes one factor. Water, H2O, is only a chemical union of O and H. Iron rust, Fe2O3 and H2O, is composed of O, Fe, and water. The burning of wood or of coal gives rise to carbon dioxide, CO2, and water. ”

“ In chemical stability these triatomic compounds, considered as a group, are in a marked degree below the diatomic ones. The various sugars and kindred bodies, decompose at no very high temperatures. The oils and fats also are readily carbonized by heat. Resinous and gummy substances are easily made to render up some of their constituents. And the alcohols, with their allies, have no great power of resisting decomposition. These bodies, formed by the union of oxygen, hydrogen, and carbon, are also, as a class, chemically inactive. Formic and acetic are doubtless energetic acids ”

“ Oxygen and nitrogen, nitrogen and hydrogen, hydrogen and carbon, which show no affinity for each other under ordinary circumstances, readily unite when one or both are in a nascent condition. The reason seems to be that, when the elements of a compound are torn asunder, the chemical affinity which previously bound them together is set free, ready and eager to unite the nascent elements with whatever they come in contact with. ”

“ May we not, therefore, conclude that the chemical action exhibited in a burning body is a development of some latent force, with which we are unacquainted, produced by the absorption of light;—that a repulsive action at first takes place, by which the hydrogen and carbon are separated from each other;—and that in the nascent state they are seized by the oxygen, and again compelled, though in the new forms of water and carbonic acid, to resume their chains of combining affinity? ”

“ Expert Analysis.—A modification of this experiment is employed by experts to test for AS2O3 poisoning. The organs.— stomach or liver—are cut into small pieces dissolved by nascent Cl, or HClO, made from KC1O3 and HCl, and the solution is introduced into a H generator, as above. AS2O3 preserves the tissues it comes in contact with, for a long time, and the test can be made years after death. All the chemicals must be pure, since As is found in small quantities in most ores, and the Zn, HCl, and H2SO4 of commerce are very likely to contain it. ”

“ We know that, floating around us, these volatilized bodies exist in some material form, and numerous experiments in chemistry are calculated to convince us, that the most attenuated air is capable, with a slight change of circumstances, of being converted into the condition of solid masses. Hydrogen gas, the lightest, the most ethereal of the chemical elements, dissolves iron and zinc, arsenic, sulphur, and carbon; and from the transparent combinations thus formed, we can with facility separate those ponderous bodies. Such substances must exist in our own atmosphere ”

“ The Decomposition of any remaining Portion, and the adoption of measures best calculated to obviate its absorption. Where the substance is in a solid form, and acts by absorption, we should be very cautious how we favour its solution; while, if it exists in a liquid state, our object must be to render its active portion insoluble; this problem involves a series of questions which are wholly chemical. In order to prevent, or retard, the absorption of the active matter, we must, to a great degree, depend upon the agency of vital adjuvants ”

“ See Experiment 124. Study Figure 29, and write the reactions. 2 HNO3 breaks up into 2 NO2, H2O, and O. 94. Importance.—Sulphuric acid has been called, next to human food, the most indispensable article known. There is hardly a product of modern civilization in the manufacture of which it is not directly or indirectly used. Nearly a million tons are made yearly in Great Britain alone. It is the basis of all acids, as Na2CO3 is of alkalies. It is the life of chemical industry, and the quantity of it consumed is an index of a people's civilization. ”

“ That many of these hydrocarbons would be solid at ordinary temperatures, forming the so-called mineral wax, which exists in many places in large quantities, is much easier to imagine, in the light of modern chemical knowledge, than that the fatty acids were at once split up into the simpler liquid hydrocarbons, to be afterward condensed into the more complex molecular forms of the solid substance. ”

“ Thus we find 'inflammable air* as the name for hydrogen, 'fixed air* for carbonic acid gas, and 'dephlogisticated marine acid air' for chlorin. That no better principle of classification of substances from a chemical standpoint than that of superficial outward appearance was demanded is not strange, when we recollect that at this period and, indeed, down to the close of the eighteenth century, the transmutation of metals was a popular belief of the common people and was not disproved by the chemist. ”

“ But as soon as the solution is rendered stronger, or the solvent and the dissolved body are endowed with a mutual chemical affinity, chemical reactions set in. Part of the molecules of the dissolved body dissociate, and the atoms of which they were composed, on being set free, combine with the atoms of the solvent. Chemical forces, much more energetic than the physical forces, enter into play, and most complicated chemical reactions—the intensity of which may be judged of from the changes of temperature—begin. ”

“ Water, from its extensive powers as a solvent, never occurs in a state of absolute purity, although the nature and degree of its contamination must necessarily vary according to circumstances and situation. It is generally found holding earthy matter in a state of mechanical suspension, or saline and other bodies in chemical solution. ”

“ From the beginning to the end the student is surprised and delighted with the developments of the exact discrimination, as well as the power and capacity, which are displayed in various forms of chemical action. Dissolve two substances in the same fluid, and then, by evaporation or otherwise, cause them to reassume a solid form, and each particle will unite with its own kind, to the entire exclusion of all others. Thus, if sulphate of copper and carbonate of soda are dissolved in boiling water, and then the water is evaporated, each salt will be reformed as before. ”

“ The new acid and the lime spring to each other and combine together at once, while the colourless carbonic acid gas is thrown off into the air. What power is this, that the new acid possesses? What makes the lime throw up its alliance with the gas? I believe myself that it is intimately connected with a law that exists throughout creation both in the animate and inanimate world,—that opposite natures should be drawn together. Inorganic substances which have the strongest “attraction” for one another, are those which differ most entirely in their qualities. ”

“ It brings home to me what an unstable chemical compound man is. Here are the stage accessories as good as ever, while the players have all split up into hydrogen and oxygen and nitrogen and carbon, with traces of iron and silica and phosphorus. ”

“ The destruction of organic matter through simple distillation by means of pure hydrochloric acid is at least equal to that by sulphuric acid, chlorate of potash, and the carbonisation methods. The object of the chemist not being to dissolve every fragment of cellular tissue, muscle, and tendon, but simply all mineral ingredients, the less organic matter which goes into solution the better. ”

“ Although it may appear that some cases of chemical combination are due to these powers,—as, for instance, when the union of oxalic acid or sulphuric acid with lime produces an insoluble salt,—we cannot thus explain the constant proportions in which the metals, sulphur, oxygen, and similar bodies, unite. It is quite certain there is a power or principle, which we [Pg 286] have not yet reached, upon which are dependent all the phenomena which we now embrace under the term chemical affinity. ”

“ Chemical Composition. When pure it consists of oxygen, hydrogen, and carbon; the rectified æther however still contains some water and alcohol, for Lovitz obtained an æther of 632. Solubility. One part requires for its solution ten of water; with alcohol and ammonia it unites in every proportion. Solvent Powers. It is one of 268the most powerful solvents known in vegetable chemistry, as it dissolves balsams, resins, gum-resins, wax, camphor, extractive, &c.; it takes up about a twentieth of its weight of sulphur, but it exerts no solvent power upon the fixed alkalies. Forms of Exhibition. ”

“ The first class includes such substances as iodine, mercury, iron, carbon, and their various compounds, and such bodies as alcohol, chloroform and chloral, all of which are found in nature or can be prepared by ordinary chemical processes of manufacture. From plants many substances are obtained which at the present time we are unable to make in the chemical laboratory, and of the constitution or composition of which we are in many cases ignorant. ”

“ Organic compounds, on which our life and living depend, consist chiefly of four elements: carbon, hydrogen, oxygen and nitrogen. These compounds are sometimes hard to analyze, but when once the chemist has ascertained their constitution he can usually make them out of their elements—if he wants to. He will not want to do it as a business unless it pays and it will not pay unless the manufacturing process is cheaper than the natural process. ”

“ Since normal solutions of various reagents are all referred to a common standard, they have an advantage not possessed by empirical solutions, namely, that they are exactly equivalent to each other. Thus, a liter of a normal solution of an acid will exactly neutralize a liter of a normal alkali solution, and a liter of a normal oxidizing solution will exactly react with a liter of a normal reducing solution, and so on. ”

“ In smokeless powder the oxygen is held in chemical union with nitrogen and hydrogen, but the bond between the nitrogen and the other elements is weak, so that when ignited the other more active elements are enabled easily to unite at the expense of the nitrogen. ”

“ It was formerly supposed that the substances found in plants and animals, mostly complex compounds of carbon, hydrogen and oxygen, could only be produced by "vital forces." If this were true it meant that chemistry was limited to the mineral kingdom and to the extraction of such carbon compounds as happened to exist ready formed in the vegetable and animal kingdoms. But fortunately this barrier to human achievement proved purely illusory. The organic field, once man had broken into it, proved easier to work in than the inorganic. ”

“ How might NH4Cl be obtained from the NH4OH in the Woulff bottles? (6) Test the liquid in each bottle with red litmus paper. (7) Add some from the first bottle to 5 or 10 cc. of a solution of FeSO4 or FeCl2, and look for a ppt. State the reaction.
99. Formation.—Ammonia, hartshorn, exists in animal and vegetable compounds, in salts, and, in small quantities, in the atmosphere. Rain washes it from the atmosphere into the soil; plants take it from the soil; animals extract it from plants. Coal, bones, horns, etc., are the chief sources of it, and from them it is obtained by distillation. ”

“ Such an arrangement, if erected upon a scale sufficiently extensive, with the medium of a neutro-saline solution, would, in his opinion, produce large quantities of acids and alkalies with very little trouble or expense.
249 Alterations in chemical equilibrium are constantly taking place in Nature, and he thinks it probable that the electric influence, in its faculties of decomposition and transference, may considerably interfere with the chemical changes occurring in different parts of our system. ”