To take the case of smoking, very few smokers realize, in the first place, how much money they expend. It is money which, if not spent, would appreciably contribute to the cost of house-keeping in not a few cases. Many a man who says he cannot afford to marry spends on tobacco and alcohol a sum quite sufficient to turn the scale. It will be argued that the smoking brings rest and peace, that it soothes, aids digestion, and so forth. But the non-smoker is not in need of these assistances: it is only the smoker who requires to smoke for these purposes. On this point I have said, in the volume of personal hygiene which this present work is meant to succeed, all that really requires to be said. It was there pointed out that nicotine doubtless produces secondary products in the blood which require a further dose of the nicotine as an antidote to them. Thus there is initiated a vicious circle, the details of which have been fully worked out in the case of opium, or rather, morphia. All the good results which are obtained from smoking are essentially of the nature of neutralizing the secondary effects of previous smoking. Here, then, is the scientific argument for the girl's hand if she proposes to deal with her lover on this point. It may be added that the writer can now quote personal experience in favour of his advice. He smoked incessantly for fourteen years--from seventeen to thirty-one--his quantum being five ounces in all per week--of the strongest Egyptian cigarettes and the strongest pipe tobacco procurable. The practice did him no observable harm whatever. When he wrote the paragraph on "How to control one's smoking," in the book referred to, he was only wishing that he could control his own. At last he got disgusted with himself and stopped altogether. Personally he is neither better nor worse, but he is buying books in proportion to the money formerly wasted on tobacco, and perhaps the change is worth while. The girl who reads this book may tell her lover with confidence that it is quite possible to stop smoking, and that after a little while the craving wholly disappears. If he has been a really confirmed, systematic smoker, he may have a very uncomfortable three weeks after he stops, but soon after that the time will come when he can stay in a room where others are smoking and not even desire to join them, which he could never have done before. He will have the advantage that he is definitely less likely to die of cancer of the mouth, more especially cancer of the tongue. That is a point which will affect his wife as well as himself. He will save a quite remarkable sum of money, and since object lessons are very valuable, he may follow the suggestion to lay it out in the form of books, as time goes on, though perhaps my reader can give him better advice from the point of view of the future housekeeper. Of course there is the point of view expressed in a poem of Mr. Kipling's: