At this time of life, too, anaemia,, or bloodlessness, is particularly prevalent among those who work in overcrowded, close rooms, with many gas lights. It is especially prevalent among young girls who sit for a large number of hours together in such rooms, and the only cure for it is change of occupation ; it is perfectly hopeless to do anything else.

Eheumatic fever is very prevalent among young people, from catching cold. This is a much more serious disease than is commonly thought, because it consists of inflammation of the fibrous tissues of the body, among which are the serous membranes of the joints, and among the serous membranes that are sometimes inflamed are the two that are inside and outside the heart - the endocardium and the pericardium; and when this happens it frequently causes a permanent alteration of the valves of the heart, so that those valves no longer act properly, and we have what is called valvular heart disease ; this always gets worse, and cannot get better ; it gets worse during the rest of life, and invariably shortens it, so that every possible precaution to prevent young people from getting rheumatic fever should be taken. It is not a communicable disease, like scarlet fever, whooping-cough, or measles, and has not the property of communicable diseases, that having had it once you cannot take it again ; but, on the contrary, when you have had rheumatic fever once you are more likely to have it again, and if you do not get heart disease the first time you are very likely to get it the second time.

In manhood, the diseases we get are especially chronic diseases, and many of them result from having diseases in youth, for instance chronic rheumatism, and the most important thing during manhood is to take care not to eat too much food. In manhood, all that has to be replaced is the losses that are continually taking place; there is no increase in weight, we remain stationary at the same weight, or about the same, for some years; there are slight variations, but they are of no importance whatever ; any great variation from the ordinary weight during manhood is to be regarded suspiciously ; any great increase in weight shows that a man is either taking too much food or not enough exercise, or both ; and it should be remembered, in connection with this, that in manhood a man should not leave off his exercise; he should take as much exercise as he finds, practically speaking, good for him, without tiring himself too much, or he will increase in weight, and begin to age sooner than he ought. On the other hand, any decrease in weight is to be regarded suspiciously, because it is likely to be the sign of some disease; nevertheless, the variation of a few pounds either way is of no importance whatever.

At or before middle age the results of habits begin to show themselves, and the result of one habit, that of drinking alcoholic liquors, begins to show itself sometimes in a very marked manner. It is at this time that those persons who have been accustomed to drink small quantities of spirits during the day begin to find that they have something the matter with the liver; a man begins to find out that he has a liver, in fact. The fibrous structures of the liver are increased, they grow at the expense of the proper liver structure, and they compress it, and so press upon the small branches of the portal vein which brings the blood to the liver, and the blood is prevented from circulating through the liver in the way in which it ought to be circulated; it is resisted by the structure of the liver, and so the liquid part gets through the walls of the capillary vessels into the peritoneal sac-^-that sac which is folded in and about the organs of the abdomen-and the result is dropsy of the abdomen. Now, this particular kind of liver is quite easily distinguished, and is so thoroughly well recognised as being caused by drinking alcohol, that it goes among physicians by the name of the gin drinker's liver. The result of this disease is death, which is caused in several ways, sometimes by the fluid becoming so great in amount that it presses upon the diaphragm, impedes the action of the lungs and heart, and causes death, you may almost say, by suffocation. The habit of drinking spirituous liquors during life does not always result in this, but it often results in a bad form of indigestion. There are various reasons why the drinking of alcohol causes indigestion. I shall speak more about them when I come to speak about foods and drinks; but I want to point out here that we pay much too little attention to indigestion, and the drinking of alcoholic liquors is certainly the first cause of indigestion. If our food be not properly digested it cannot be absorbed, the tissues of the body cannot be nourished, and they degenerate, so that alcohol causes degeneration of the tissues indirectly by causing indigestion, and causes degeneration directly by reason of its presence in the blood, and so spirit-drinkers, whether they have this liver- disease or not, have degeneration of the various tissues of the body, and so they have other diseases of the internal organs.

Another thing that it is extremely important to attend to during this period of life is the action of the excretory organs of the body; the action of these organs tends to become languid, and the most important ones to attend to are the skin and the intestinal canal. The action of the skin should be attended to by frequent washing, because if the surface of the skin is not properly cleansed its action will be impeded; and the other excretory organs-the lungs and the kidneys-will have to do the work of the skin, and these organs will be liable to become diseased, so there is no doubt whatever that a large number of the diseases of the lungs and kidneys during manhood, and during the later periods of life, is to a great extent due to insufficient action of the skin.

During this period of life such diseases as diabetes, kidney disease, gout, and chronic lung diseases, aip very common, and some of the causes of them are those I have just mentioned.