ANALYSIS, in chemistry, is the term applied to that department of experimental science which has for its object the chemical disunion or separation of the constituents of a compound substance: thus, the resolution of water into its components, hydrogen and oxygen; of common salt into chlorine and sodium; of marble into lime and carbonic acid; of rust into iron and oxygen; of sugar into carbon, hydrogen, and oxygen; and of chloroform into carbon, hydrogen, and chlorine—are all examples of chemical A. This department of chemistry, therefore, takes cognizance of the breaking down of the more complex or compound substances into their more simple and elementary constituents, and is antagonistic to chemical synthesis, which treats of the union of the more simple or elementary bodies to produce the more complex or compound. Chemical A. is of two kinds : Qualitative A., which determines the quality or nature of the ingredients of a compound, without regard to the quantity of each which may be present; and quantita tive A., which calls in the aid of the balance or measure, and estimates the exact propor Lion, by weight or volume, in which the several constituents are united. Thus, qualitative A. informs us what water, marble, common salt, etc., are composed of; but it remains for quantitative A. to tell us that water consists of 1 part of hydrogen by weight united with 8 parts of oxygen; that marble is composed of 28 parts of lime and 22 of carbonic acid: common salt, of 35k parts of chlorine and 23 of sodium; turpentine, of 30 carbon and 4 hydrogen; chloroform, of 12 carbon, 1 hydrogen, and 1061 chlorine.
The divisions of inorganic (mineral) chemistry and organic (vegetable and animal) chemistry have led to a corresponding classification of chemical A. into inorganic A., comprehending the processes followed and the results obtained in the investigation of the atmosphere, water, soils, and rocks; and organic A., treating of the modes of isolation and the nature of the ingredients found in or derived from organized structures—viz., plants and animals. Both departments afford examples of what are called proximate and ultimate A. Proximate A. is the resolution of a compound substance into components
which are themselves compound: thus, in inorganic chemistry, marble is resolved into lime (calcium united with oxygen) and carbonic acid (carbon with oxygen): whilst ulti• mate A. comprehends the disunion of a compound into its elements or the simplest forms of matter: thus, lime into calcium and oxygen; carbonic acid into carbon and oxygen, water into hydrogen and oxygen. Organic chemistry affords still better examples of each class: thus, ordinary wheat-flour, when sujected to proximate A., yields, as its proximate components, gluten (vegetable fibrin), albumen, starch, sugar, gum, oil. and saline matter; but each of these proximate ingredients is in itself compound, and when they undergo ultimate A., the gluten and albumen yield, as their ultimate elements or constituents, carbon, hydrogen, oxygen, nitrogen, sulphur, and phosphorus; and the starch, sugar, gum, and oil are found built up of carbon, hydrogen, and oxygen.
Several other terms are in use in chemical treatises: thus Gas A. is applied to the processes employed in the examination of the various gases, and is every day becoming of more and more importance and interest. Metallurgic A. includes the smelting of metallic ores, the assays of alloys of gold, silver, etc., and, in general, everything that pertains to the ultimate A. of metallic ores and compounds. Agricultural A. is restricted to the examination of manures, feeding-stuffs, and soils; medical or physiological A. to the investigation of blood, urine, and other animal fluids and juices, and the examination of medicinal compounds; whilst commercial A. is the term used where great accuracy or nicety of detail is not required in an A., but where the commercially important constitu ents alone are determined, as the separation and recording of the amount of phosphates, ammonia, and alkaline salts in a sample of guano; the total amount of saline matter in a certain water; the iron in an iron-stone, the lime in a limestone, etc.