Word Finder - chemistry

definition

The branch of natural science that deals with the composition and constitution of substances and the changes that they undergo as a consequence of alterations in the constitution of their molecules.

definition

An application of chemical theory and method to a particular substance.

definition

The mutual attraction between two people; rapport.

I think it's something about my body chemistry that they don't like.

The Chemistry of the Sun (1887) is an elaborate treatise on solar spectroscopy based on the hypothesis of elemental dissociation through the intensity of solar heat.

So well was his position as a leading man of science now established that in 1854 he was appointed professor of chemistry and dean of the Faculte des Sciences at Lille.

An exact and conscientious worker, he did much to improve and systematize the processes of analytical chemistry and mineralogy, and his appreciation of the value of quantitative methods led him to become one of the earliest adherents of the Lavoisierian doctrines outside France.

From about 1796 Ampere gave private lessons at Lyons in mathematics, chemistry and languages; and in 1801 he removed to Bourg, as professor of physics and chemistry, leaving his ailing wife and infant son at Lyons.

In chemistry he made a speciality of the platinum metals.

He was thus led to conclude that chemistry is a branch of applied mathematics and to endeavour to trace a law according to which the quantities of different bases required to saturate a given acid formed an arithmetical, and the quantities of acids saturating a given base a geometrical, progression.

The number of periodicals devoted to chemistry has steadily increased since the early part of the 19th century.

Utilitarian, or perhaps rather practical, considerations have very little to do with the subject from a scientific point of view - no more so than the science of chemistry has to do with the art of the manufacturing chemist.

During recent years chemistry has become one of the most important subjects in the curriculum of technical schools and universities, and at the present time no general educational institution is complete until it has its full equipment of laboratories and lecture theatres.

Organic chemistry was especially developed by the publication of Gerhardt's Traite de chimie organique in 1853-1856, and of Kekule's Lehrbuch der organischen Chemie in 1861-1882.

Their full significance is treated in the section of this article dealing with organic chemistry, and in the articles Isomerism and STEREO-Isomerism.

Inorganic Chemistry Inorganic chemistry is concerned with the descriptive study o f the elements and their compounds, except those of carbon.

The earliest discoveries in inorganic chemistry are to be found in the metallurgy, medicine and chemical arts of the ancients.

The 18th century witnessed striking developments in pneumatic chemistry, or the chemistry of gases, which had been begun by van Helmont, Mayow, Hales and Boyle.

Before leaving this phase of inorganic chemistry, we may mention other historical examples of allotropy.

Klaproth, and especially by Berzelius; these chemists are to be regarded as the pioneers in this branch of descriptive chemistry.

After having been somewhat neglected for the greater attractions and wider field presented by organic chemistry, the study of the elements and their inorganic compounds is now' rapidly coming into favour; new investigators are continually entering the lists; the beaten paths are being retraversed and new ramifications pursued.

It thus happened that in the earlier treatises on phlogistic chemistry organic substances were grouped with all combustibles.

Bergman worked in the same direction; while Rouelle was attracted to the study of animal chemistry.

At the same time, however, he adhered to the classification of Lemery; and it was only when identical compounds were obtained from both vegetable and animal sources that this subdivision was discarded, and the classes were assimilated in the division organic chemistry.

The exact delimitation of inorganic and organic chemistry engrossed many minds for many years; and on this point there existed considerable divergence of opinion for several decades.

Notwithstanding these errors, the value of the " ethyl theory " was perceived; other radicals - formyl, methyl, amyl, acetyl, &c. - were characterized; Dumas, in 1837, admitted the failure of the etherin theory; and, in company with Liebig, he defined organic chemistry as the " chemistry of compound radicals."

An apt definition of organic chemistry is that it is "the study of the hydrocarbons and their derivatives."

Analytical Chemistry This branch of chemistry has for its province the determination of the constituents of a chemical compound or of a mixture of compounds.

The germs of analytical chemistry are to be found in the writings of the pharmacists and chemists of the iatrochemical period.

The acid finds considerable use in organic chemistry, being employed to discriminate between the different types of alcohols and of amines, and also in the production of diazo, azo and diazo-amino compounds.

The chemistry of the albumins is one of the most complicated and difficult in the whole domain of organic chemistry.

This list is not exhaustive; other products are given in Gustav Mann, Chemistry of the Proteids (1906), to which reference should be made for a complete account of this class of compounds.

Several journals are published specially to deal with physical chemistry, of which electrochemistry forms an important part.

Among them may be mentioned the Zeitschrift fiir physikalische Chemie (Leipzig); and the Journal of Physical Chemistry (Cornell University).

The name is applied in commerce to a complex mixture of carbohydrates obtained by boiling starch with dilute mineral acids; in chemistry, it denotes, with the prefixes d, 1 and d+l (or i), the dextro-rotatory, laevo-rotatory and inactive forms of the definite chemical compound defined above.

Weber, The Chemistry of Indiarubber (London, 1902); Selected papers from the Kew Bulletin, iii.

In addition to many other researches besides those here mentioned, he wrote or edited various books on chemistry and chemical technology, including Select Methods of Chemical Analysis, which went through a number of editions; and he also gave a certain amount of time to the investigation of psychic phenomena, endeavouring to effect some measure of correlation between them and ordinary physical laws.

Thomson (Applications of Dynamics to Physics and Chemistry, 47) that on dynamical principles there must be a reciprocal relation between the changes of dimensions produced by magnetization and the changes of magnetization attending mechanical strain.

In 1844, having graduated as doctor of medicine and doctor of science, he was appointed to organize the new faculty of science at Besancon, where he acted as dean and professor of chemistry from 1845 to 1851.

But his most important work was in inorganic and thermal chemistry.

But his best known contribution to general chemistry is his work on the phenomena of reversible reactions, which he comprehended under a general theory of " dissociation.

The principal contributors to the " Transactions " of this section of the academy were--for anatomy and physiology, Coloman Balogh, Eugene Jendrassik, Joseph Lenhossek and Lewis Thanhoffer; for zoology, John Frivaldszky, John Kriesch and Theodore Margo; for botany, Frederick Hazslinszky, Lewis Juranyi and Julius Klein; for mineralogy and geology, Joseph Szabo, Max Hantken, Joseph Krenner, Anthony Koch and Charles Hoffman; for physics, Baron Lorando Eotviis, Coloman Szily and Joseph Sztoczek; for chemistry, Charles Than and Vincent Wartha; for meteorology, Guido Schenzl.

Thus he carried on the narrative of orderly development from the point at which it was left by Kant and Laplace - explaining by reference to the ascertained laws of physics and chemistry the configuration of the earth, its mountains and seas, its igneous and its stratified rocks, just as the astronomers had explained by those same laws the evolution of the sun and planets from diffused gaseous matter of high temperature.

Finally, it brought the simplest living matter or formless protoplasm before the mental vision as the startingpoint whence, by the operation of necessary mechanical causes, the highest forms have been evolved, and it rendered unavoidable the conclusion that this earliest living material was itself evolved by gradual processes, the result also of the known and recognized laws of physics and chemistry, from material which we should call not living.

Thus mysticism was finally banished from the domain of biology, and zoology became one of the physical sciences - the science which seeks to arrange and discuss the phenqmena of animal life and form, as the outcome of the operation of the laws of physics and chemistry.

General Tendencies Since Darwin Darwin may be said to have founded the science of bionomics, and at the same time to have given new stimulus and new direction to morphography, physiology, and plasmology, by uniting them as contributories to one common biological doctrine-the doctrine of organic evolution-itself but a part of the wider doctrine of universal evolution based on the laws of physics and chemistry.

Uranyl nitrate is used in photography, and also in analytical chemistry as a precipitant for phosphoric acid (as uranyl ammonium phosphate, U02 NH4 P04).

Then, after a short time in Liebig's laboratory at Giessen, and in the Sevres porcelain factory, he became in 1841 professor of chemistry in the academy of Geneva.

In physical chemistry he carried out many researches on the nature and process of solution, investigating in particular the thermal effects produced by the dilution of saline solutions, the variation of the specific heat of saline solutions with temperature and concentration, and the phenomena of liquid diffusion.

Pathological chemistry has been remarkable chiefly for the knowledge we have obtained of the nature of bacterial poisons.

In this doubtless he derived much advantage from his knowledge of chemistry, though the science was as yet not disentangled from the secret traditions of alchemy, and was often mixed up with imposture.

Van Helmont (1578-1644) was a man of noble family in Brussels, who, after mastering all other branches of learning as then understood, devoted himself with enthusiasm to medicine and chemistry.

Its chief aim was to reconcile the new views in physiology and chemistry with practical medicine.