blended with either of the others. They may be effectively studied in the aggregate, in different races of men. The English would seem to possess a happy blending in this respect. The Belgians, especially the better class, afford a fair sample of the sanguine-lymphatic; the latter element preponderating in the temperament of the Dutch. The northern Germanic races- -the Swedes and Norwegians—are more or less pure examples of the 'sanguine;' while the temperament of the Chinese and Mongolians is essentially lymphatic. In individuals there is every possible variety. This natural impression received by the body at birth, and forming part of the constitution, must be studied and taken into consideration, especially in the earlier years of life, when the system is yet pliable as the twig, and by external agencies may have any tendency imparted.

The formidable word 'idiosyncrasy'* has been applied to certain peculiarities and susceptibilities of system. It may be illustrated by facts drawn from every-day life. Thus, of three persons exposed to the same degree of cold and damp, the first may suffer in consequence, from pulmonary affection-the second, from rheumatismand the third, from derangement of the digestive organs; or if similarly exposed to some contagion, all being previously in full health, one may fall a victim, and the other two escape. dose of any given medicine administered to two persons placed under similar circumstances, will affect them very differently.

The same

Hereditary predisposition must also be taken

*From three Greek words:-dos proper, oùv together, and xgãois mixture-signifying peculiar admixture.

as

into account. It is well known that certain characteristic peculiarities arise, and are transmitted in families. The thickness of lip of the imperial house of Austria is an instance from history; as well as the fact, that to several Roman families peculiar names were applied, denoting some striking peculiarity of nose, lips, or other features. Mental and psychical as well as physical characters are thus inherited. Unfortunately, the inheritance comprises weaknesses as well better qualities; the diseases, whether mental or bodily, from which the father has suffered, frequently re-appearing in the son, and again in his descendants. How fearful are the ravages made by consumption, generation after generation, in certain families; carrying off its victims in the pride of youth, beauty, and intellect. The gout, too, with what punctuality it visits the elderly representatives of numerous families, particularly of the rich and noble. These and other hereditary predispositions show themselves at particular periods of existence-some in childhood, others in maturity, and many towards the decline of life. How important to take these into consideration in reference to the action of physical agents upon health! If the child with strumous or consumptive tendency, be reared in a damp, badly-ventilated, dark abode, the disease will assuredly show itself: and should he, when grown up, have offspring, it will be developed in these with even greater intensity. Every effort then, should be directed to give physical vigour to the body in infancy and childhood, so that it may throw off hereditary weakness. In effecting this object, the influence of proper clothing and

diet, free exposure to good air, and to the light of heaven is incalculable.

Habit is the garb which man assumes in compliance with physical or social necessity. It frequently conceals the original nature and constitution, and may therefore be regarded as a secondary or surface nature. Much of our every-day life may be traced to it-our hours of rising and repose, of fasting and feeding, our capabilities of endurance and exertion. Through it, man can accommodate himself to almost any climate or condition. What can be more remarkable than the way in which he becomes adapted through habit to different kinds of diet? The Esquimaux enjoys his blubber or seal's flesh, the Polynesian his bananas and yams; some American Indian tribes regard clay as a luxury; Indians use asafoetida as a seasoning, while other races eat messes that a European would loathe! Habit results from the influence of external or internal impressions on the mind. This is exerted in different ways. In one case the mind is struck by some new impression conveyed through one of the senses; the impression on being repeated, creates less sensation than at first, and if repeated frequently, will at last pass unheeded. Thus any loud noise, when first heard, excites attention, but fails to do so when we are used to it. The miller is rather soothed than not by the sound of his mill; and as an illustration of habit, we may notice the anecdote of the man who woke earlier than usual one morning because a cannon in his vicinity was not discharged at the regular time. It is from habit, that the eye becomes accustomed to very strong or weak light, the nose to offensive

odours, and the palate to peculiar flavours. Habit again may result from the attention being directed to certain impressions, which, in consequence, become more fixed; or to certain acts which become perfected thereby-a new set of associations being thus established in the mind. If these impressions are of pleasurable character, we all know how apt we are to desire their renewal; and, moreover, there seems a natural tendency in the mind to repetition, which at last may occur independently of the will. It is in infancy that habits are most easily acquired; the sensibility is then fresh, the tissues are soft and impressible, "like flexible wax which the fingers of the artist -the parent-may fashion." The habits acquired in early life materially affect the future, and, what we have to consider, the future health of the individual. Habits relating to diet, clothing, sleep, exercise, cleanliness, &c., are mostly of early growth, and become more or less part of ourselves in proportion as they have been inculcated in childhood. Manhood is, alas! more apt to expend itself in fruitless regrets than in attempts at improvement. It would be useless to enter into any detailed notice of bad habits; their name is legion, but they must be taken into consideration as forming part of the individual.

Every age or period of life has its characteristic peculiarities, from the infant "mewling and puking in the nurse's arms to the last scene of

"Second childishness, and mere oblivion;

Sans teeth, sans eyes, sans taste, sans everything."

The blood circulates with different degrees of rapidity and force, the functions are performed

with varying energy, and the mind as well as body exhibits peculiar phases at different epochs of existence. The conditions necessary to life and health-the rules relating to clothing, cleanliness, food, air, and exercise-though essentially the same for every age, must be modified with each. Without dividing human existence, after Shakspere, into seven ages, it may be observed that there are well-marked periods connected with development, which require special care and attention. During infancy, children, like the young of other animals, are guided almost entirely by instinct, and beyond the impulses which this imparts, depend on others for the fulfilment of conditions necessary to their well-being. During dentition, too great attention cannot be paid to the general health, to the maintenance of the temperature of the body, the free admission of air, and regulation of diet. But it is in childhood, when the processes of nutrition and development are in full energy, when the system is plastic and yields readily to external influences, that the tendency may be imparted which shall determine the subsequent well-being of the individual. As is the child, so, even in a physical sense, will in all probability be the man. How much sickness and mortality might be diminished by attention to the laws of health in early life! What is it, but want of proper nourishment and clothing, of effective light and pure air, that prevents or retards maturity in the children of the poor inhabitants of large towns? Much may yet be done to place these in better circumstances; and the children of the wealthier classes, who are compelled to pass the greater part of the year in