Early Distinction between Inorganic and Organic Chemistry.
The development of organic chemistry in the course of the nineteenth century is a subject so vast that it is mentioned in this place with something approaching despair. The great chemists who, in the latter part of the eighteenth and in the early years of the nineteenth century, had rescued their science from the superstitious and fantastic theories and conceits which had encumbered it, Lavoisier, Priestley, Scheele, Cavendish, Dalton, Fourcroy, Berzelius, and many others who might be named, distinguished sharply between the products of the mineral kingdom and those which they called organic, that is, substances of vegetable or animal origin, combined, it was agreed, under the influence of what was described as vital force. This force, it was considered, inherent in living bodies, could never be imitated in the laboratory, and its achievements were beyond human skill. It was even doubted whether the elements composing organic substances were subject to the same laws of combination as were those of the mineral world.
Lavoisier, it is true, regarded organic bodies as consisting of radical compounds, hydrocarbon radicals, as he called them, instead of the metallic bases. His last scientific work was the investigation of the statics of organic chemistry, and on this subject his clear vision would probably have enabled him to anticipate many modern conclusions. He had already recognised some of the transformations of sugar, had analysed alcohol, and had declared that in animal and vegetable chemistry no less than in the inorganic kingdom nothing is ever destroyed, but that vegetation and animalisation are only inverse phenomena of combustion and putrefaction.
Synthetic Organic Compounds.
Some isolated results of the artificial productions of organic substances are recorded which do not seem to have been recognised as challenging the reign of vital force. Scheele, in 1786, formed oxalic acid by oxidising sugar by nitric acid; and in 1822 Döbereiner produced formic acid, previously known as a distillate of ants, by oxidising tartaric acid. In both these cases, however, the transformation was essentially one from a previous organic substance.
The inauguration of synthetic chemistry is understood to date from the year 1828 when Wöhler, then a professor of chemistry at Berlin, produced a supposed cyanate of ammonium by the action of ammonium chloride on silver cyanate. Wöhler was surprised to find the cyanate of ammonium which he had obtained did not correspond with other ammonium salts, but resembled, and as he afterwards proved, was identical with the organic substance, urea, a crystalline compound which constitutes about half of the solid matter dissolved in urine. Wöhler and Liebig next collaborated in a study of organic substances, and one of the early results of their investigations was the discovery of the compound radical, benzoyl, as they termed it, C7H5O, which they found could be combined with chlorine, bromine, iodine, sulphur, ammonium, and other substances, always retaining its own individuality. It was, in fact, a compound radical, and though it has never been isolated, its compounds prove its character. Berzelius was so struck by this discovery that he suggested the name of proine or orthrine, either meaning the dawn, in substitution for benzoyl.
Friedrich Wöhler.
(From the Royal Collection of Etchings at Munich.)
Born at Eschersheim, near Frankfort, 1800; died at Göttingen, 1882. Wöhler’s notable discovery of the artificial production of urea in 1828 is famous as the starting point of synthetic chemistry.