This section is from the book "Health", by W. H. Coefield.
These are the three chief temperaments of the ancient writers, but another, called the bilious temperament, is often mentioned. This, however, we do not now consider a temperament, because it is not due to a predominance of one of the general systems of the body.
The great mass of human beings do not belong markedly to any one or other of these temperaments, and so persons who insist upon the division have invented the mixed temperaments.
Celsus pointed out that human beings, after being divided into these large classes according to their temperaments, might be divided into much smaller ones. He taught that each human being had what he called his weak point, of which he had to take special care, in order that he might ward off the diseases to which he himself was more specially liable than the people around him. These minor divisions are called idiosyncrasies. An idiosyncrasy is a tendency to excess or defect in any given limited direction, a peculiarity in the action of any particular organ of the body, or particular apparatus of the economy. They are of very various kinds, some of them apparently very unimportant ; but those that are unimportant form illustrations, and explain to us and make us better understand those that are of great importance. Now, there are idiosyncrasies (to take some of the comparatively unimportant first, in order that you may quite understand what I mean) of the organs of the senses. Some people there are who cannot bear the taste of strawberries; that is an example of an idiosyncrasy, and a very peculiar one.
There are plenty of instances of persons who cannot sit at a dinner-table when certain things are on the table; for instance, a leg of mutton. Now, these are idiosyncrasies of taste and smell.
Now, to pass on to idiosyncrasies which more immediately concern the subject in hand. Persons are liable, as Celsus pointed out, to particular diseases. One person is peculiarly liable to certain diseases to which another person next him may not be liable; and that other person may be liable to diseases of another kind, and that is what Celsus meant to insist upon.
Several persons exposed to a draught may get very different diseases from it, if they get any; one person gets a sore throat, another person gets bronchitis, another a cold in the head, another quinsy. Why is that ? That is because, as Celsus said, each person has his weak point, which is liable to be attacked whenever he is exposed to a cause of disease, and each person should take care to find out what is his particular weak point, in order that he may ward <?flf the disease to which he is liable. His weak point very often has come to him by heredity; very often he has had an attack of disease for some reason or another which, in the first instance, we may not be able to explain. He has caught a very severe cold, and had some form of lung disease, and for the rest of his life he is more liable to an attack of disease in that part of the body than anywhere else A person who has once had sore throat is more likely to have sore throat than he was before, so that you see idiosyncrasies may be acquired, may be formed.
A capital example of this is found in the case of a regiment of soldiers who encamp on marshy ground for a night; one of them gets ague of one form or another, another one gets a cold in the head, another rheumatic fever, another is subject to chronic rheumatism, and gets an attack of " rheumatics," another gets inflammation of the lungs, another bronchitis, another pleurisy, another a sore throat, another toothache, and another gets nothing at all Well, all these people get these different diseases from the same cause, from exposure to damp atmosphere, because they were weak in different points, because they had different idiosyncrasies. I say, then, it is of the first importance for everybody to find out what is the point about his own system which is most likely to be attacked, and take precautions against it.
Certain diseases, or tendencies to disease, are inherited. Why do we inherit a tendency to disease? We are not at all surprised if a son or a daughter is like either his or her father, or mother, or grandfather, or grandmother in the face; then, why should we be astonished that they are like them in the lungs or liver ? If they are like them in external features, why should they not be like them in the construction of their internal organs? It is clear enough there is no reason why it should not be so, and it is the case; and not only do likenesses of that kind descend in families, but peculiar construction of organs descend, peculiar construction of features descend, and not only so, but incidental peculiarities descend.
There are plenty of instances where peculiarities have descended in families, where, for instance, a person has had six fingers on one hand, and the same peculiarity has occurred in his descendants. A notable example is that of the short-legged sheep, which were produced by a farmer in North America some years ago, who found accidentally that one of his sheep had got the two fore-legs short. That was an accident, or a monstrosity of nature, and it occurred to this farmer that it would be very useful if he could get the rest of his sheep so, because he need not have his hedges so high ; and so, by careful selection of the young ones, he produced a race of sheep which all had their fore-legs short. So you see that accidental peculiarities descend in families, and so it is that peculiarities in the construction of the internal organs of the body descend, and that tendencies to disease are hereditary. There are a few diseases that actually descend, in which the child is born in a state of disease.
One of the most marked examples of hereditary tendency to disease is found in consumption, the plague of our climate. This terrible disease kills more than half as many people as all the zymotic diseases (fevers, etc.) put together. There is no doubt that a tendency to consumption descends in families. I do not mean to say that consumption cannot start in any family. If you go and expose yourselves to the causes by which consumption is brought about, although there may be no tendency to consumption in your family, consumption may arise in you, and may be inherited from you. So, too, scrofulous diseases are hereditary.