DISCOVERY OF BENZOL.

New Zealand Herald, Volume LXII, Issue 19061, 4 July 1925, Page 12

DISCOVERY OF BENZOL.

FARADAY THE CHEMIST. CELEBRATION OF CENTENARY. The centenary of Faraday's announcement of the discovery of benzol was celebrated in London last month. Writing in the Times, Professor Henry Armstrong said that thoso who are posted in the history of electrical discovery have long been accustomed to regard the Royal Institution in London as the. birthplace of the electrical power plant, which plays so important a part in our modern civilisation. Few realise/ however, the extent, to which it has been the focus point of chemical discovery the foundation stone of the edifice of. theoretical chemistry, as Well as that of our modern dye-stuff and dyeing industries, was laid there by-the act of the great Faraday. Faraday was equally competent as chemist and as physicist, in fact, ho began life as chemical assistant to the famous Sir Humphry Davy; all his early work was chemical and he passed from chemistry to physics over an electro-chemical bridge which he himself built. Faraday's discovery of benzene—better known, to motorists especially, as benzol—was made known to tile Royal Society of London on June 16, 1825. A century ago before tho days of gas lighting, Londoners were supplied by the Portable Gas Company with gas similar to that which has been much used, in recent years, in lighting railway trains; it was made by decomposing fish oil at a. r«d heat and compressing the gas into iron cylindors. Faraday, who took great interest in technical processes, separated benzene from tho liquid condensed in the cylinders during the compression of the gas,. He determined its properties wifch'>xt&otdinary acumen. ; Benzene is perhaps the most wonderful substance known to the chemist and yet it consists merely of, half-a-dozen' atoms 6f carbon, taken hexagonally, cm bloc, from a layer in tho diamond and associated with half-a-dozen atoms of hydrogen placed at the six corners of the hexagon. By introducing various other atoms or groups of atoms in place of these hydrogen atoms, chemists have prepared thousands upon thousands of derivatives, each a fixed entity with distinctive properties ; in fact, the study of tho derivatives of benzene has engaged the attention of a majority of chemists during the past half-century.

Derivatives of benzene are largely used by Nature as building materials in plant and animal structures; many are of medicinal value. Apart from blood-red, leafgreen and a few of tho yellows, all the natural vegetable colours aro derived from benzene; so are all the artificial. The structure chemists have built upon Faraday's foundation is not only colossal, but a. firm 'one; indeed, a certainty little short of absolute may be claimed for their deductions; so iVock is this the. case that physicists who are turning the X-rays upon chemists' work aro in agreement that there is little left for them to do .bat confirm chemists' pronouncements.