An additional observation concerning the vegetative functions is, that they, like all others, admit of great modifications, nay, even of idiosyncrasies. Some persons on account of their innate vigor and strong constitution succeed under all circumstances: they resist all noxious influences, they digest whatever they eat, whilst others suffer from particular aliments, such as mutton, pigeon, veal, cauliflower, &c. These latter and all other particularities can only be observed, but can never be explained. In regard to them, every one must be his own physician. DEMOSTHENES and HALLER were kept in a state of regular excitement by drinking nothing but water. Coffee was the favorite stimulus of VOLTAIRE, and tea that of Dr. JOHNSON. Sir ISAAC NEWTON lived upon vegetables when he was employed in composing his famous treatise on Optics. HOBBES sat in his study, enveloped in the smoke of tobacco, &c. In general, however, a strict attention to physical education cannot be insisted upon too much among civilized nations. During the periods of life, from birth to the state of full growth, a third kind of laws is to be kept in view, and these shall be considered in the following pages.

CHAPTER III

ON THE LAWS OF EXERCISE.

THESE laws embrace what is called Education in a more limited sense, but in this respect many errors are caused by the true meaning of the word Exercise not being sufficiently understood. I employ this expression as synonymous with putting into action, and distinguish Exercise from Habit; the latter being the result of the former.

Habit.

Habit has two significations: it sometimes indicates the result of diminished activity, and at other times a greater facility of acting. A power being too active, becomes fatigued, diminishes, and is finally exhausted. Moreover, all natural powers become accustomed to external impressions, and the former become the less affected the longer the latter are applied. The mimosa sensitiva, when shaken for a certain time, ceases to fold its leaves. In the same way, each sort of impression on the organization loses its effect by frequent

repetition. Even noxious impressions, when repeated, are less felt than they were at first. In this sense MITHRIDATES accustomed his stomach and bowels to poisonous substances. The attendants and nurses of patients become in a certain degree insensible to contagious diseases in hospitals. The mind itself shows less energy at each repetition of the same functions. It becomes accustomed even to misfortune and painful situations. Time is a great remedy of many evils.

Organized beings adapt themselves in a surprising degree to external impressions, and a change of place and various circumstances is frequently less advantageous than might have been expected. Prisoners, who have been confined for many years to dungeons, or unwholesome habitations, fall sick when they obtain their liberty. Many morbid, but accustomed affections, such as old sores and exudations, &c. are to be removed with the greatest precaution, and sometimes to be left untouched. Body and mind successively take a turn which can be changed solely by degrees.

All changes which nature produces are successive, and art ought to imitate her proceedings. It is the same in dietetic rules, and in every manner of feeling and thinking. Drunkards cannot leave off their bad habits suddenly without injuring their health. Those who are near starving from inanition, will perish if too much nourishment be

given; and too much light dazzles those who have lived long in darkness. The bad effects of great and sudden changes of temperature on inanimate bodies, such as glass, or on plants, animals, and man, are generally known. Those who are accustomed to certain mental occupations, feel great reluctance to give them up. In the same way, great and sudden changes of politi cal, moral, and religious opinions, are not borne with indifference. Habit is a second nature, physically and morally speaking.

The living generation, if not prepared for it, generally rejects every reform. It is only in process of time that the adherents to any new doctrine become numerous; and any doctrine, though false, when once admitted, will be replaced by another and a better only by degrees. Yet it is natural that the more agreeable a doctrine is, the sooner it will gain ground, and that a precept which commands resignation will be submitted to, in proportion to the reward it promises. Christianity assigns eternal happiness as the reward for temporal conflicts; and it was adopted by fishermen and the poor sooner than by the rich.

The law of modifying mankind, or of producing changes is seldom understood by reformers. They are commonly too hasty; though, at all times, experience has shown the danger and harm of such a proceeding. When changes are to be

made, let them be gradual; the greater the alterations you wish for are, the slower must be your method of proceeding; keeping, however, constantly the aim in view. The precipitancy of common reformers can be excused only by their ignorance of human nature, and by their errone ous opinion, that it is sufficient to point out errors, and to propose principles, in order to perfect man without considering that he must by degrees be prepared for, and accustomed to them.

The facility of accommodating man to new impressions greatly depends on age; it succeeds best during the period of growth, whilst in latter years we are less susceptible of changes. It is therefore not astonishing, that all new doctrines have been received and propagated by youth and new generations.

The law of accommodation, however great, never annihilates the general laws of life. It is even subordinate to them, and cannot prevent the successive changes of age. Again, every individual being born with a different constitution, and with different dispositions, is not equally capable of accommodating himself to circumstances, and hence each will present some modification, though the external influences are the same. This is the case in the automatic and animal functions. Notwithstanding these restrictions, the law of accommodation is incalculably great in the education both of individuals and of nations.