Base (chemistry)

“ This appears very curiously in his chapters on the philosophy of Chemistry. He recommends, as a judicious use of "the degree of liberty left to our intelligence by the end and purpose of positive science," that we should accept as a convenient generalization the doctrine that all chemical composition is between two elements only; that every substance which our analysis decomposes, let us say into four elements, has for its immediate constituents two hypothetical substances, each compounded of two simpler ones. ”

“ The serial system of the chemical elements, which forms so important a topic of consideration in recent chemistry, is a notable example of how various masses of facts which once seemed in certain respects ultimate and mutually sundered, tend, upon further examination, to assume their places as stages of a single, though highly complex, order-system. ”

“ Thus, even in Chemistry, limits are set to the successful adoption of the purely mechanical point of view, by the fact that chemical combination is regularly productive of new qualities in the compound which could not have been predicted from a knowledge of the properties of its constituents, but have to be ascertained a posteriori by actual experiment. ”

“ Into the attraction of aggregation, or cohesion; and chemical attraction, or affinity. The former takes place between particles which are similar, and the latter between those which are dis-similar. All the operations of chemistry are founded upon the force of affinity which Nature has established between the particles of different kinds of matter, and which enables the chemist to produce new compounds differing more or less from the substances by whose union they were formed. ”

“ In brief, though the chemist, in his account of an element or a compound, may refer to certain physical traits associated with its molecular constitution and affinities, he does not by so doing change these into chemical traits. Whatever chemists may put into their books, Chemistry, considered as a science, includes only the phenomena of molecular structures and changes—of compositions and decompositions.12 I contend, then, that Chemistry does not give an account of anything as a concrete whole, in the same way that Biology gives an account of an organism as a concrete whole. ”

“ We now know that many compounds exist which are formed by the union of the same quantities by weight of the same elements, and, nevertheless, differ in properties; modern chemistry explains this fact by saying that the properties of a substance depend, not only on the kind of atoms which compose the minute particles of a compound, and the number of atoms of each kind, but also on the mode of arrangement of the atoms.3 The same doctrine was taught by Lucretius, two thousand years ago. ”

“ Analyze the atomic theory of modern chemistry and you will find that all that makes it significant for chemical practise is expressible in this way: If any two substances unite with each other chemically, they do so in such a manner that there are no particles of them so small as not to follow the same law of combination that holds for the substances in bulk. ”

“ It is not easy to define what chemistry is in a few words, but it may be described as the science which has for its object the investigation of all elementary bodies which exist in the universe, with the view of determining their composition and properties. It also seeks to detect the laws which regulate their mutual relations, and the proportions in which these elements will combine together to form the compounds which constitute the animal, vegetable, and mineral kingdoms, as well as the properties of these various compounds. ”

“ Nature’s Chemistry—Changes produced by Chemical Combination—Atomic Constitution of Bodies—Laws of Combination—Combining Equivalents—Elective Affinity—Chemical Decomposition—Compound Character of Chemical Phenomena—Catalysis or action of Presence—Transformation of Organic Bodies—Organic Chemistry—Constancy of Combining Proportions—The Law of Volumes, the Law of Substitutions, Isomeric States, &c.
All things on the earth are the result of chemical combination. The operations by which the commingling of molecules and the interchange of atoms take place, we can imitate in our laboratories ”

“ Numerous phenomena of even a more striking character than those selected, are exhibited in every department of chemistry; but within the limits of this essay it is impracticable to speak of any beyond those which directly explain natural phenomena.
The chemical elements, which actually exist in nature as simple bodies, are probably but few. Most of the gases are in all probability compounds of some ethereal ultimate principles; and with the advance of science we may fairly hope to discover the means of reducing some of them to a yet more simple state. ”

“ PROFESSOR OF CHEMISTRY AND PHYSICS IN THE UNIVERSITY OF CINCINNATI.
WHAT are the so-called chemical elements? Are they really elements, or only compounds of remarkable stability? It would be hard to find in physical science a question which has been oftener asked than this. It has furnished all sorts of investigators with abundant food for speculation. Men of the highest scientific ability have grappled with the problem, and left it still unsolved; others have constructed elaborate theories, which claimed to settle everything. ”

“ All the great speculative questions of modern chemistry must be eventually fought out upon the battle-field of physics.
Now, having recognized some facts concerning the intellectual future of chemistry, let us inquire what material steps will best lead up to them. What experimental work is most needed to begin with? Plainly, if we are to discover laws connecting the physical properties of compounds with their composition, we must first determine the physical properties of the elements. ”

“ Then molecules which cannot be seen and cannot be manipulated as individual, but can be discovered only by chemical apparatus, are found by analysis and synthesis to exhibit many homologies, and the science of chemistry undertakes this enterprise. ”

“ That they might think clearly and suggestively about the properties of elements, and connect these with other chemical facts, they have translated the language of sense-perceptions into the language of thought, and, for properties of those substances which have not been decomposed, have used the more fertile expression atomic properties. When a chemist thinks of an atom, he thinks of the minutest particle of one of the substances which have the class-mark have-not-been-decomposed, and the class-name element. ”

“ Even if the theory of atoms were abandoned, the generalisation would remain, as an accurate and exact statement of facts which hold good in every chemical change, that a number can be attached to each element, and the weights of the elements which combine are in the ratios of these numbers, or whole multiples of these numbers. ”

“ If the compound he desires to produce is found to be composed of elements different from those which form the compound wherewith his operations begin, he is directed to bring about a reaction, or a series of reactions, between the compound which is to be changed, and some other collocation of elements the composition of which is known to be such that it can supply the new elements which are needed for the production of the new compound. ”

“ The present tendency of chemical research is evidently towards a still greater development of organic chemistry, and an increased application of physics and mathematics to chemical theory and practice. ”

“ The observed residual phenomena of nature which yet await solution are many and varied; every branch of scientific work presents its own list. Let me glance at a few, and they shall be chiefly chosen from those phenomena which are investigated by the science of chemistry.
That the molecules of the elements, i. e., the smallest individual parts which exhibit the properties of the elements, consist of yet smaller parts, or atoms, is undoubted. The generalization holds, with few exceptions, that the elementary molecules contain each two atoms. ”

“ For our purpose the chemical aspect is the most important, and therefore, before developing the law and its consequences, we will consider the chemical phenomena from which the law is deduced or which it serves to explain. ”

“ The practical side of organic chemistry should never be lost sight of for a moment, and under no condition should the course be allowed to deteriorate into one of mere picturing of structural formulæ on the blackboard. All chemical formulas are merely compact forms of expression of what we know about chemical compounds. There are, no doubt, many facts about chemical compounds which their accepted formulas do not express at all, and the wise teacher should lead the student to see this. ”

“ Accepting the truth of the above law, the question naturally arises as to whether there is any limit to the various chemical transformations, or are they unrestricted in number—that is to say, is it possible from a given substance to obtain an equivalent quantity of any other substance? ”

“ As to the possibility of a further analysis of our supposed simple bodies, we may venture to say that, in regard to such supposed simple bodies as compose a numerous and well-characterized class, no such step can be made, except through some great change in chemical theory, which gives us a new view of all the general relations which chemistry has yet discovered. ”

“ Introduction to general inorganic chemistry. *$2.25. Century.
The work of one who understands the psychology of teaching. The first four chapters deal in an introductory manner with the general characteristics of chemical phenomena. The remainder of the text treats elements and their compounds. “These chapters deal largely with the simpler physical properties of matter and include a brief and clear exposition of the utility of scientific method; following closely are the usual methods of determining equivalents, use of symbols and various simple calculations.”—Bookm. ”

“ To these questions we can only answer, by referring to the history of chemistry;—by pointing out what chemists have understood by analysis, according to the preceding narrative. They have considered, as the analysis of a substance, that elementary constitution of it which gives the only intelligible explanation of the results of chemical manipulation, and which is proved to be complete as to quantity, by the balance, since the whole can only be equal to all its parts. It is impossible to maintain that new substances may not hereafter be discovered ”

“ In general terms, it may be said that all chemistry, at least all theoretical chemistry, properly belongs to the province of physical chemistry, and the title, while in many ways convenient, is misleading. ”

“ The properties of matter are so distributed among the elements that three of them—Oxygen, Hydrogen, and Carbon—possess an ensemble of unique characteristics. The number of reactions in inorganic chemistry are relatively few, but in organic chemistry—in the chemistry of these three elements the number of different compounds is practically unlimited. ”

“ The great importance of physical data of this description, and the advantage of having them well determined, will be obvious, if we consider, that a list of them, when taken in combination with the general law, affords the means of determining at once the exact proportion of the ingredients of all natural compounds, if we only know the place they hold in the system. In chemistry, the number of admitted elements is between fifty and sixty, and new ones are added continually as the science advances. ”

“ The results of the experimental examination of the compositions and properties of substances, made since the time of the alchemists, have led to the modern conception of the chemical element, and the isolation of about seventy or eighty different elements. No substance now called an element has been produced in the laboratory by uniting two, or more, distinct substances, nor has any been separated into two, or more, unlike portions. ”

“ 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. ”

“ A. Crum Brown defined chemical constitution as the order in which the constituents are united in the compound, and pointed out that the study of chemical changes (composition and decomposition) cannot lead us to a knowledge of the relative position of the atoms. But such a knowledge is required before a real theory of chemistry can be attained, and a knowledge of the intimate structure of matter may be looked for from an examination of the physical properties of substances, and a comparison of these with their chemical constitution. ”

“ We are now come to the last branch of chemistry, which comprehends the most complicated order of compound beings. This is the animal creation, the history of which cannot but excite the highest degree of curiosity and interest, though we often fail in attempting to explain the laws by which it is governed. ”

“ The fundamental task of inorganic chemistry is still connected with the classification of elements and compounds. The investigation of the classification of carbon compounds forms the field of organic chemistry; while general or physical chemistry deals with the laws of reaction, and the influence of various forms of energy in furthering or hindering chemical change. ”

“ The capacity of each element to combine with one or another element, and to form compounds with them which are in a greater or less degree prone to give new and yet more complex substances, forms the fundamental character of each element. ”