Gilbert Newton Lewis

We frequently define an acid or a base as a substance whose aqueous solution gives, respectively, a higher concentration of hydrogen ion or of hydroxide ion than that furnished by pure water. This is a very one sided definition.

Since hydrogen is a constituent of most of our electrolytic solvents, the definition of an acid or base as a substance which gives up or takes up hydrogen ion would be more general than the one we used before, but it would not be universal.

We may say that a basic substance is one which has a lone pair of electrons which may be used to complete the stable group of another atom, and that an acid is one which can employ a lone pair from another molecule in completing the stable group of one of its own atoms.

It must be admitted that science has its castes. The man whose chief apparatus is the differential equation looks down upon one who uses a galvanometer, and he in turn upon those who putter about with sticky and smelly things in test tubes.

In the snobbery of science, each branch attempts to rise in the social scale by imitating the methods of the next higher science and by ignoring the methods and phenomena of the sciences beneath.

To inquire into the origin of life is like seeking the origin of electrical machinery or the origin of music. Every increase in complexity of arrangement, of form, of substance, leads to new and often incalculable properties.

Sometimes I think that our laboratories are but little earthworks which men build about themselves, and whose puny tops too often conceal from view the Olympian heights; that we who work in these laboratories are but skilled artisans compared with the man who is able to observe and to draw accurate deductions from the world about him.