Chemical reduction

“ Use and Abuse of Chlorine. Inasmuch as chlorination has no beneficial effect on water except the reduction of the bacterial content it should be used for this purpose only and under such conditions as permit the operations to be under full control at all times. The supplies that can be most efficiently and safely treated are those that are relatively constant in chemical composition and bacterial pollution. Changes in volume can be dealt with by automatic apparatus but sudden changes in organic and bacterial content require a change of dosage that cannot be made by any mechanical appliance. ”

“ 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. ”

“ It may be accomplished by distillation, which is the most perfect method; by filtration through sand, crushed charcoal, and other porous substances, which deprives it of suspended impurities and living organisms; by boiling, which destroys the vitality of all animal and vegetable matters, drives out the gases and precipitates carbonate of lime, which composes the crust frequently seen upon the inside of tea-kettles or boilers; by the use of chemical agents, which may be employed to destroy or precipitate the deleterious substances. ”

“ Analysis has advanced so rapidly of late that we may confidently anticipate that we shall soon discover wherein their aptitude really consists; having ascertained the cause, we shall next be able to command it, and to produce at our pleasure the desired effects. It is easy, even in our present state of ignorance, to reduce our ordinary food to carbon, or to lime; a moderate advancement in chemical science will speedily enable us, we may hope, to create, with equal facility, food from substances that appear at present to be as ill adapted to sustain us. ”

“ They absorb oxygen from the surrounding medium, air or water, and, in addition to certain inorganic substances, take into their bodies, as their proper nutritive material, complicated protein compounds, which they derive either directly or indirectly from plants. Through the oxidation of these compounds they form substances of a simpler chemical structure, such as carbonic acid, water, and ammonia, and discharge these through their bodies as waste. ”

“ In addition to the sources of pollution of the atmosphere which we have been considering, there are various trades and manufactures in which poisonous matters are given off. Some of these are of an organic nature, as in the melting of fats, in the making of size and glue, in the boiling of oil, in the boiling of bones, and in many other processes carried out on a considerable scale, where the emanations are highly offensive and often of unknown chemical composition. ”

“ Although the details of the process vary considerably, according to the presence or absence of air, the ultimate products of decomposition and putrefaction are in both cases the same: namely, free nitrogen, free hydrogen, ammonia, methane, carbonic acid and sulphuretted hydrogen. These are also the end-results of the disintegration of the human body. ”

“ Our review of production has shown the impossibility of doing so, unless we completely wipe out the organic chemical industry which is essential for world progress by its contribution of dyes, drugs, and other synthetic commodities. ”

“ In larger works where dust is generated this should be drawn away at the point where it is produced. This applies also to processes in the chemical industries where lead or lead compounds are used, seeing that no substitute is possible. ”

“ It came to be employed extensively for absorbing ammonia in the illuminating-gas industry, which was in its infancy one hundred years ago. New industries such as the manufacture of “superphosphates” as artificial fertilizers, the refining of petroleum, the manufacture of artificial dyestuffs and many other modern chemical products have greatly increased the demand for it, while its employment in the production of nitric and other acids, and for many other purposes not already mentioned, has been very great. ”

“ 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. ”

“ And it has been stated by an eminent authority in such matters that we might save 500,000 tons of coal a year by economizing the waste heat of furnaces, by purifying the coal, coking it, etc. In a single chemical manufactory, out of about two thousand tons of hydrochloric acid used per annum, about eight hundred tons have been allowed to flow away as a polluting substance, because it was not possible to utilise it. The loss of material from a single large glass works equals fourteen hundred tons per annum, and a value of £8,000. ”

“ The clumsy, unclean and inconvenient use of wood and coal for fuel is with us a practice of the past.
“But chemistry has done for us an immeasurably greater service. It has enabled us to provide for ourselves a food supply by the process of synthesis, which, in the extremity of crop shortage or failure, we can [Pg 90] resort to as a means of averting famine. You are aware, in your present stage of chemical knowledge, that all food products are composed of four simple ingredients, Carbon, Oxygen, Hydrogen and Nitrogen, found in abundant supply in the atmosphere and its natural mixture. ”

“ Hence, as putrefaction is impossible in the absence of moisture, and the active agent, albumen, equally reduced, decomposition of such substances that remain ensues only by a process of decay, slow combustion or oxidation, the slowly uniting of oxygen with the substance. In this the constituent parts of the animal tissues break up into simpler compounds by the chemical changes that nature produces, and differs from other forms of putrefaction only by the length of time employed. ”

“ A man, like a steam-engine, can not move without his appropriate fuel; and if the fuel is not supplied, the fire goes out and the man dies. The exact manner in which the materials are utilized for keeping up this vital flame is the question to which we must now address ourselves.
Food-stuffs and coal agree essentially in the chief characteristics of their chemical constitution. Both consist mainly of hydrogen and carbon, and both possess energy in virtue of the fact that their affinities for oxygen are not satisfied. Water contains hydrogen, and carbonic acid contains carbon ”

“ For fuel a pound of coal is about equal to two pounds of wood, and a pound of gasoline to three pounds of wood in heating value, so there would be a great loss in efficiency and economy if the world had to go back to a wood basis. But when that time shall come, as, of course, it must come some time, the wood will doubtless not be burned in its natural state but will be converted into hydrogen and carbon monoxide in a gas producer or will be distilled in closed ovens giving charcoal and gas and saving the by-products, the tar and acid liquors. ”

“ There can be no doubt that this complexity, if not immediately, is then gradually, lessened in the animal economy. There are probably countless stages in the oxidation into urea of each particle of nitrogenous tissue, be it cell-wall or cell-protoplasm, and at each stage of the process the particle will have consequently less potential energy and greater chemical stability ”

“ Wood, peat, charcoal, bones, or shells are cleaned for carbon-14 dating in order to remove every trace of possible contamination by modern carbon as well as extraneous old carbon. Rocks are crushed and ground, minerals are separated according to what is needed in any particular study, and the desired elements are extracted and separated by chemical procedures. ”

“ Inspired by nature, a large body of research has been devoted to new materials catalyzing CO2 functionalization in either electrochemical or chemical ways. In 2009, the US start-up Carbon Science [2] has produced liquid fuels thanks to a prototype. The demonstration prototype uses Carbon Science innovative biocatalytic process to break down CO2 and water and then combines carbon and hydrogen to form ethanol, a liquid fuel. Enzymes from microorganisms transform CO2 and H2O to methane, methanol, and butanol. ”

“ The general method of procedure which has yielded the best results, is to remove the adsorbed hydrocarbons by various processes of combined oxidation and distillation, whereby the hydrocarbons of high boiling points are broken down into more volatile substances and removed at lower temperatures, or under conditions less likely to result in subsequent deposition of inactive carbon. Thin layers of charcoal and rapid gas currents are used so that contact between the volatilized hydrocarbons and the hot active charcoal may be as brief as possible. ”

“ The substitution between oxygen and hydrogen is very rarely accomplished by the reaction of the free elements, but the substitution between these elements, one for another, forms the most common case of oxidation and reduction. ”

“ Reflection will also show us how inconvenient it would be if chemical affinity existed at all distances; if coal, for instance, were to combine with oxygen without the application of heat, it would greatly alter the value of this fuel to mankind, and would materially check the progress of human industry. ”

“ Those actions of light which have been last referred to are called by the chemist reducing actions, a term which he applies to the cases in which a compound is made to part with its oxygen or other similar element: when the remaining ingredient is a metal, the operation by which the other has been removed is always called reduction. ”

“ The action of a plant upon the air is therefore the separation of combustible material from that medium. Carbon is thus obtained from carbonic acid; from water, hydrogen. Plant life is chemically an operation of reduction, for in like manner ammonia is decomposed into its constituents, which are nitrogen and hydrogen; and sulphuric and phosphoric acids, which like ammonia, may have been brought into the plant through its roots in the form of salt bodies, are made to yield up the oxygen with which they had been combined, and their sulphur and phosphorus, combustible elements, are appropriated. ”

“ As the result of laboratory experiments designed to show the effect of the violent escape of vapour produced below the surface of molten metal in causing contamination of the air, and the nature of the contaminating substances, he was able to conclude that the chemical action of the materials (acid and flux) used, and subsequent vaporization of the products of this action, was a much more important factor than the mechanical action of escaping vapour. ”

“ Great Chemical Industries. Thus it is that our Government today [Pg 368] is giving most serious heed to the need of building up a great chemical industry in the United States. We have the raw materials. We need only the factories and the trained men that go with them. We need, of course, in addition to the development of the coal tar industry, a production of heavy chemicals such as chlorine, sulfuric acid and the like, all of which, however, are bound together by community interest in peace as well as in war. ”

“ If we are ever to get ahead, if we are to gain any respite from this enormous waste of labor and natural resources, we must find ways of preventing the iron which we have obtained and fashioned into useful tools from being lost through oxidation. ”

“ The most useful new chemical processes are those used in purifying water sewage and milk, in electroplating metals and other substances, in the application of chemicals to the fine arts, in extracting grease from wool, and the making of many useful products from the waste materials of the dumps and garbage banks. ”

“ The tactful hostess, the salon leader, is a social catalyst. The trouble with catalysts, either human or metallic, is that they are rare and that sometimes they get sulky and won't work if the ingredients they are supposed to mix are unsuitable.
But the uranium, osmium, platinum or whatever metal is used as a catalyzing agent is expensive and although it is not used up it is easily "poisoned," as the chemists say, by impurities in the gases. The nitrogen and the hydrogen for the Haber process must then be prepared and purified before trying to combine them into ammonia. ”

“ The chemical industry is also one of the most dynamic sectors in most countries, including many developing ones. Yet this industry, together with its products, can have a particularly severe impact on the environment. I has given rise to a host of new problems both of product and process pollution. It continues to generate an increasingly wider rang of products and wastes whose effects, especially long-term ones, on human health and the environment are not precisely known. Major accidents have taken place, and the safety record of the industry has been challenged in recent years. ”