Mat 22, 1908] 



SCIENCE 



811 



light — what has chemistry done to improve 

 artificial illumination? In ancient times 

 animal and vegetable oils and fats, waxes 

 and resins, were used for illumination in 

 lamps, candles and torches. The flames 

 must have been extremely smoky, odorous 

 and generally disagreeable. It was in the 

 early eighteen hundreds that the stearic- 

 acid candle was introduced, following 

 Chevreul's pioneer work on the chemistry 

 of the animal and vegetable oils and fats. 

 It was later still when crude petroleum was 

 refined by the chemist and kerosene and 

 gasoline came into general use for lighting 

 and heating. Coal gas, the discovery of 

 Clayton in 1675, was first used for illu- 

 mination in modern times by Wm. Mur- 

 doch in 1792, who lighted his own house 

 with it. Now illuminating gas of one kind 

 or another issues from orifices in the earth 

 in various places and the Chinese at an 

 early day made use of this gas for 

 evaporating salt brine and for lighting salt 

 factories. But no general use was made 

 of either natural or artificial gas until the 

 early eighteen hundreds. In the United 

 States at the present time more than $200,- 

 000,000 is invested in gas plants, and the 

 gas industry is, of course, a chemical in- 

 dustry developed by chemists. But with 

 gas flames as with other flames, more of 

 the energy is dissipated as heat than is 

 radiated as light, and for many years the 

 problem of obtaining a larger percentage 

 of the energy of combustibles in the form 

 of light was an unsolved problem. It was 

 known that certain oxides, such as those 

 of calcium and magnesium, emitted a bril- 

 liant light when heated, but these oxides 

 were brittle and a mantle made of them 

 would crumble and fall apart. But with 

 the discovery of new elements and the 

 investigations of their properties, oxides 

 were finally found which, when heated, 

 emitted an intense light and at the same 

 time were tough enough to construct a 



mantle of. Auer von Welsbaeh took out 

 his first patents for glow lights or gas 

 mantles made of thorium and cerium 

 oxides in 1886. Edison constructed the 

 first successful filament for an incandescent 

 lamp out of a charred bamboo filament, 

 but now the demand is for more light from 

 the incandescent bulb, and the tantalum 

 lamp and the tungsten lamp are already 

 practically successful and others will fol- 

 low. 



So much for the contributions of chem- 

 istry to the art of illumination. I might 

 take the matter of food chemistry and 

 show some most interesting developments. 

 How larger and better corn crops are now 

 produced than formerly, due in part to the 

 application of chemistry to corn breeding; 

 how the sugar beet has been raised from 

 6 per cent, to 8 per cent, of sugar content, 

 to 18 per cent, or 20 per cent. ; how the 

 sugar cane and the cereals are being im- 

 proved; how the scientific application of 

 fertilizers is maintaining soils in a state of 

 fertility ; and how the great science of soil 

 chemistry is developing with enormous 

 rapidity. Think what that means. It 

 means the food-supply of future genera- 

 tions and life and health to them. Agri- 

 culture is fundamental in human affairs, 

 and chemistry is fundamental in scientific 

 agriculture. 



In every branch of human knowledge 

 and activity, the influence of chemistry is 

 making itself felt. Under its influence the 

 people are beginning to note that it is tbe 

 composition of things, not appearances and 

 not names, that is important. I am as 

 great an admirer as any man of the human 

 imagination in science and in art. I am 

 capable of appreciating keenly the romance 

 in literature and impressionism in paint- 

 ing, and I can enjoy, too, that combina- 

 tion of romance and impressionism which 

 the advertising man places before our 

 vision in vending his wares. I am capable 



