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See also:BARON JUSTUS VON See also:LIEBIG (1803-1873)
, See also:German chemist, was See also:born at See also:Darmstadt, according to his baptismal certificate, on the 12th of May 1803 (4th of May, according to his See also:mother)
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His See also:father, a drysalter and dealer in See also:colours, used sometimes to
make experiments in the See also:hope of finding improved processes for the See also:production of his wares, and thus his son See also:early acquired familiarity with See also:practical See also:chemistry
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For the theoretical See also:side he read all the See also:text-books which he could find, somewhat to the detriment of his -See also:ordinary school studies
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Having determined to make chemistry his profession, at the See also:age of fifteen he entered the See also:shop of an See also:apothecary at Appenheim, near Darmstadt; but he soon found how See also:great is the difference between practical See also:pharmacy and scientific chemistry, and the explosions and other incidents that accompanied his private efforts to increase his chemical knowledge disposed his See also:master to view without regret his departure at the end of ten months
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He next entered the university of See also:Bonn, but migrated to See also:Erlangen when the See also:professor of chemistry, K
.
W
.
G
.
Kastner (1783-1857), was appointed in 1821 to the See also:chair of physics and chemistry at the latter university
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He followed this professor to learn how to analyse certain minerals, but in the end be found that the teacher himself was ignorant of the See also:process
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Indeed, as he himself said afterwards, it was a wretched See also:time for chemistry in See also:Germany
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No laboratories were accessible to ordinary students, who had to content themselves with what the See also:universities could give in the lecture See also:room and the library, and though both at Bonn and Erlangen See also:Liebig endeavoured to make up for the deficiencies of the See also:official instruction by See also:founding a students' See also:physical and chemical society for the discussion of new discoveries and speculations, he See also:felt that he could never become a chemist in his own See also:country
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Therefore, having graduated as Ph.D. in 1822, he See also:left Erlangen—where he subsequently complained that the contagion of the " greatest philosopher , and metaphysician of the See also:century " (See also:Schelling), in a See also:period " See also:rich in words and ideas, but poor in true knowledge and genuine studies," had cost him two See also:precious years of his See also:life—and by the liberality of See also: By the help of L . J . See also:Thenard he gained See also:admission to the private laboratory of H . F . Gaultier de Claubry (1792-1873), professor of chemistry at the Ecole de Pharmacies and soon afterwards, by the See also:influence of A. von See also:Humboldt, to that of See also:Gay-Lussac, where in 1824 he concluded his investigations on the See also:composition of the fulminates . It was on Humboldt's See also:advice, that he determined to become a teacher of chemistry, but difficulties stood in his way . As a native of Hesse-Darmstadt he ought, according to the academical rules of the time, to have studied and graduated at the university of See also:Giessen, and it was only through the influence of Humboldt that the authorities forgave him for straying to the See also:foreign university of Erlangen . After 'examination his Erlangen degree was recognized, and in 1824 he was appointed extraordinary professor of chemistry at Giessen, becoming ordinary, professor two years later . In this small See also:town his most important See also:work was accomplished . His first care was to persuade the Darmstadt See also:government to provide a chemical laboratory in 'which the students might obtain a proper practical training . This laboratory, unique of its See also:kind at the time, in See also:conjunction with Liebig's unrivalled gifts as . a teacher, soon rendered Giessen the most famous chemical school in the See also:world; men flocked from every country to enjoy its advantages, and many of the most accomplished chemists of the loth century had to thank it for their early training . Further, it gave a great impetus to the progress of chemical See also:education throughout Germany, for the continued admonitions of Liebig combined with the influence of his pupils induced many other universities to build laboratories modelled on the same See also:plan . He remained at Giessen for, twenty-eight years, until in 1852 he accepted the invitation of the Bavarian government to the ordinary chair of chemistry at See also:Munich university, and this See also:office he held, although he was offered the chair at See also:Berlin in 1865, until his See also:death, which occurred at Munich on the loth of See also:April 1873 . Apart from Liebig's labours for the improvement of chemical teaching, the influence of his experimental researches and of his contributions to chemical thought was felt in every See also:branch of the See also:science . In regard to methods and apparatus, mention should be made of his improvements in the technique of organic See also:analysis, his plan for determining the natural alkaloids and for ascertaining the molecular weights of organic bases by means of their chloroplatinates, his process for determining the quantity of See also:urea in asolution—the first step towards the introduction of precise chemical methods into practical See also:medicine—and his invention of the See also:simple See also:form of See also:condenser known in every laboratory . His contributions to inorganic chemistry were numerous, including investigations on the compounds of See also:antimony, See also:aluminium, See also:silicon, &c., on the separation of See also:nickel and See also:cobalt, and on the analysis of See also:mineral See also:waters, but they are outweighed in importance by his work on organic sub-stances . In this domain his first See also:research was on the fulminates of See also:mercury and See also:silver, and his study of these bodies led him to the See also:discovery of the See also:isomerism of cyanic and fulminic acids, for the composition of fulminic See also:acid as found by him was the same as that of cyanic acid, as found by F . See also:Wohler, and it became necessary to admit them to be two bodies which differed in properties, though of the same percentage composition . Further work on See also:cyanogen and connected substances yielded a great number of interesting derivatives, and he described an improved method for the manufacture of See also:potassium See also:cyanide, an See also:agent which has since proved of enormous value in metallurgy and the arts . In 1832 he published, jointly with Wohler, one of the most famous papers in the See also:history of chemistry, that on the oil of See also:bitter almonds (See also:benzaldehyde), wherein it was shown that the radicle benzoyl might be regarded as forming an unchanging constituent of a See also:long See also:series of compounds obtained from oil of bitter almonds, throughout which it behaved like an See also:element . See also:Berzelius hailed this discovery as marking the See also:dawn of a new era in organic chemistry, and proposed for benzoyl the names " Proin " or " Orthrin " (from 7rpn.,1 and o"pOpvs) . A continuation of their work on bitter See also:almond oil by Liebig and Wohler, who remained See also:firm See also:friends for the See also:rest of their lives, resulted in the elucidation of the mode of formation of that substance and in the discovery of the ferment emulsin as well as the recognition of the first See also:glucoside, See also:amygdalin, while another and not less important and far-reaching inquiry in which they collaborated was that on uric acid, published in '837 . About 1832 he began his investigations into the constitution of See also:ether and See also:alcohol and their derivatives . These on the one See also:hand resulted in the enunciation of his See also:ethyl theory, by the See also:light of which he looked upon those substances as compounds of the radicle ethyl (C2H5), in opposition to the view of J . B . A . See also:Dumas, who regarded them as hydrates of olefiant See also:gas (See also:ethylene); on the other they yielded See also:chloroform, See also:chloral and aldehyde, as. well as other compounds of less See also:general See also:interest, and also the method of forming mirrors by depositing silver from a slightly ammoniacal See also:solution by acet aldehyde . In 1837 with Dumas he published a See also:note on the constitution of organic acids, and in the following See also:year an elaborate See also:paper on the same subject appeared under his own name alone; by this work T . See also:Graham s See also:doctrine of polybasicity was extended to the organic acids . Liebig also did much to further the See also:hydrogen theory of acids . These and other studies in pure chemistry mainly occupied his See also:attention until about 1838, but the last See also:thirty-five years of his life were devoted more particularly to the chemistry of the processes of life, both See also:animal and See also:vegetable . In animal See also:physiology he set himself to trace out the operation of determinate chemical and physical See also:laws in the See also:maintenance of life and See also:health . To this end he examined such immediate vital products as See also:blood, bile and urine; he analysed the juices of flesh, establishing the composition of creatin and investigating its decomposition products, creatinin and sarcosin; he classified the various articles of See also:food in accordance with the See also:special See also:function performed by each in the animal See also:economy, and expounded the See also:philosophy of +cooking; and in opposition to many of the medical opinions of his time taught that the See also:heat of the See also:body is the result of the processes of See also:combustion and oxidation performed within the organism . A secondary result of this See also:line of study was the preparation of his food for infants and of his See also:extract of See also:meat . Vegetable physiology he pursued with special reference to See also:agriculture, which he held to be the See also:foundation of all See also:trade and See also:industry, but which could not be rationally practised without the guidance of chemical principles . His first publication on this subject was See also:Die Chemie in ihrer Anwendung auf Agricultur and Physiologie in 184o, which was at once translated into See also:English by See also:Lyon See also:Playfair . Rejecting the old notion that See also:plants derive their nourishment from humus, he taught that they get See also:carbon and See also:nitrogen from the carbon dioxide and See also:ammonia See also:present in the See also:atmosphere, these compounds being returned by them to the atmosphere by the processes of putrefaction and See also:fermentation—which latter he regarded as essentially chemical in nature—while their potash, soda, See also:lime, See also:sulphur, See also:phosphorus, &c., come from the See also:soil . Of the carbon dioxide and ammonia no exhaustion can take See also:place, but of the mineral constitutents the See also:supply is limited because the soil cannot afford an indefinite amount of them;- hence the See also:chief care of the See also:farmer, and the function of See also:manures, is to restore to the soil those minerals which each See also:crop is found, by the analysis of its ashes, to take up in its growth . On this theory he prepared artificial manures containing the essential mineral substances together with a small quantity of ammoniacal salts, because he held that the See also:air does not supply ammonia fast enough in certain cases, and carried out systematic experiments on ten acres of poor sandy See also:land which he obtained from the town of Giessen in 1845 . But in practice the results were not wholly satisfactory, and it was a long time before he recognized one important See also:reason for the failure in the fact that to prevent the alkalis from being washed away by the See also:rain he had taken pains to add them in an insoluble form, whereas, as was ultimately suggested to him by experiments performed by J . T . Way about 1850, this precaution was not only superfluous but harmful, because the soil possesses a See also:power of absorbing the soluble saline matters required by plants and of retaining them, in spite of rain, for assimilation by the roots . Liebig's See also:literary activity was very great . The Royal Society's See also:Catalogue of Scientific Papers enumerates 318 See also:memoirs under his name, exclusive of many others published in collaboration with other investigators . A certain impetuousness of See also:character which disposed him to See also:rush into controversy whenever doubt was See also:cast upon the views he supported accounted for a great See also:deal of See also:writing, and he also carried on an extensive See also:correspondence with Wohler and other scientific men . In 1832 he founded the Annalen der Pharmazie, which became the Annalen der Chemie and Pharmazie in 184o when Wohler became See also:joint-editor with himself, and in 1837 with Wohler and See also:Poggendorff he established the HandwOrterbuch der reinen and angewandten Chemie . After the death of Berzelius he continued the Jahresbericht with H . F .
M
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See also:Kopp
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The following are his most important See also:separate publications, many of which were translated into English and See also:French almost as soon as they ap-
peared: Anleitung zur Analyse der organischen Kerper (1837); Die Chemie in ihrer Anwendung auf Agrikultur and Physiologic (184o) ; Die Thier-Chemie See also:Oder die organische Chemie in ihrer Anwendung auf Physiologic and Pathologie (1842); Handbuch der organischen Chemie mil Rucksicht auf Pharmazie (1843); Chemische Briefe (1844) ; Chemische Untersuchungen uber das Fleisch and See also:seine Zubereitung zum Nahrungsmittel (1847) ; Die Grundsatze der Agrikultur-Chemie (1855); Ober Theorie and Praxis in der Landwirthschaft (1856); Naturwissenschaftliche Briefe fiber die moderne Land-
wirthschaft (1859)
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A See also:posthumous collection of his See also:miscellaneous addresses and publications appeared in 1874 as Reden and Abhandlungen, edited by his son See also:George (b
.
1827)
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His See also:criticism of See also: |
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