Innumerable entirely new compounds have been produced in the last century. The artificial dye-stuffs, prepared from materials occurring in coal-tar, make the natural colours blush. Saccharin, which is hundreds of times sweeter than sugar, is a purely artificial substance. New explosives, drugs, alloys, photographic substances, essences, scents, solvents, and detergents are being poured out in a continuous stream.

With all our mastery over the powers of Nature we have adhered to the view that the struggle for existence is a permanent and necessary condition of life.

The energy available for each individual man is his income, and the philosophy which can teach him to be content with penury should be capable of teaching him also the uses of wealth.

It is probable that all heavy matter possesses - latent and bound up with the structure of the atom - a similar quantity of energy to that possessed by radium. If it could be tapped and controlled what an agent it would be in changing the world's destiny! The man who put his hand on the lever by which a parsimonious nature regulates so jealously the output of this store of energy would possess a weapon by which he could destroy the earth if he chose.

Heat energy of uniform temperature [is] the ultimate fate of all energy. The power of sunlight and coal, electric power, water power, winds and tides do the work of the world, and in the end all unite to hasten the merry molecular dance.

The real value of science is in the getting, and those who have tasted the pleasure of discovery alone know what science is. A problem solved is dead. A world without problems to be solved would be devoid of science.

The dropping of the Atomic Bomb is a very deep problem... Instead of commemorating Hiroshima we should celebrate... man's triumph over the problem [of transmutation], and not its first misuse by politicians and military authorities.