Great Throughts Treasury

"So great is the effect of cleanliness upon man, that it extends even to his moral character. Virtue never dwelt long with filth; nor do I believe there ever was a person scrupulously attentive to cleanliness who was a consummate villain."

"Too much pains cannot be taken by those who write books to render their ideas clear, and their language concise and easy to be understood. Hours spent by an author in saving minutes and even seconds to his readers, is time well employed."

"When precepts fail, habits may sometimes be successful. To make vicious and abandoned people happy, it has generally been supposed, first, to make them virtuous. But why not reverse this order! Why not make them first happy, and then virtuous! If happiness and virtue be inseparable, the end will be as certainly obtained by the one method as by the other; and it is most undoubtedly much easier to contribute to the happiness and comfort of persons in a state of poverty and misery than by admonitions and punishment to reform their morals."

"Theory of heat - No reasonable objection against this hypothesis (of the incessant motions of the constituent particles of all bodies) founded on a supposition that there is not room sufficient for these motions, can be advanced; for we have abundant reason to conclude that if there be in fact any indivisible solid particles of matter (which, however, is very problematical) these particles must be so extremely small, compared to the spaces they occupy, that there must be ample room for all kinds of motion among them... And whatever the nature or directions of these internal motions may be, among the constituent particles of a solid body, as long as these constituent particles, in their motions, do not break loose from the systems to which they belong (and to which they are attached by gravitation) and run wild in the vast void by which each system is bounded (which, as long as the known laws of nature exist, is no doubt impossible) the form or external appearance of a solid cannot be sensibly changed by them... But if the motions of the constituent particles of any solid body be either increased or diminished, in consequence of the actions or radiations of other distant bodies, this event could not happen without producing some visible change in the solid body... If the motions of its constituent particles were diminished by these radiations, it seems reasonable to conclude that their elongations would become less, and consequently that the volume of the body would be contracted; but if the motions of these particles were increased, we might conclude, a priori, that the volume of the body would be expanded... We have not sufficient data to enable us to form distinct ideas of the nature of the change which takes place when a solid body is melted; but as fusion is occasioned by heat, that is to say, by an augmentation (from without) of that action which occasions expansion, if expansion be occasioned by an increase of the motions of the constituent particles of the body, it is, no doubt, a certain additional increase of those motions which causes the form of the body to be changed, and from a solid to become a fluid substance... As long as the constituent particles of a solid body which are at the surface of that body do not, in their motions, pass by each other, the body must necessarily retain its form or shape, however rapid those motions or vibrations may be; but as soon as the motion of these particles is so augmented that they can no longer be restrained or retained within these limits, the regular distribution of the particles which they required in crystallization is gradually destroyed, and the particles so detached from the solid mass form new and independent systems, and become a liquid substance... Whatever may be the figures of the orbits which the particles of a liquid describe, the mean distances of those particles from each other remain nearly the same as when they constituted a solid, as appears by the small change of specific gravity which takes place when a solid is melted and becomes a liquid; and on a supposition that their motions are regulated by the same laws which regulate the solar system, it is evident that the additional motion they must necessarily acquire, in order to their taking the fluid form, cannot be lost, but must continue to reside in the liquid, and must again make its appearance when the liquid changes its form and becomes a solid... It is well known that a certain quantity of heat is required to melt a solid, which quantity disappears or remains latent in the liquid produced in that process, and that the same quantity of heat reappears when this liquid is congealed and becomes a solid body."

"It does not appear to me that there is anything which human sagacity can fathom within the wide-extended bounds of the visible creation which affords a more striking or more palpable proof of the wisdom of the Creator, and of the special care he has taken in the general arrangement of the universe to preserve life, than this wonderful contrivance."

"If, among barbarous nations, the fear of a God and the practice of religious duties tend to soften savage dispositions and to prepare the mind for all those sweet enjoyments which result from peace, order, indust1y, and friendly intercourse, a belief in the existence of a Supreme Intelligence, who rules and governs the universe with wisdom and goodness, is not less essential to the happiness of those who, by cultivating their mental powers, have learned to know how little can be known."