When I say that consumption is hereditary, I am of course showing you that I am a believer in the microbe doctrine. So is every sensible man. The microbes of phthisis may be carried in the breath from the sick to the sound; or dried sputa—ever so little—may form dust and be breathed, thus inoculating, as it were, the person who inhales it. Not of a certainty, however, for there are many chances against those microbes, even if breathed, finding their way into the blood. Healthy blood is in itself a protection, for the white corpuscles thereof are veritable tigers in miniature, and fall upon and destroy organisms that are dangerous to the life or health of the individual. Moreover a disease germ or seed of consumption cannot, in every case, even reach the mucous membrance of the lungs, owing to the secretions therein which sweep it away, if they do not actually destroy it. On the other hand a weakly subject is far more likely to fall a victim to infection of any kind than a strong. A consumptive mother may have several children, all of which, bar one, are safe enough, though all must have inherited the evil microbe or bacillus. And this is chiefly because one is more delicate than the others. But I deem it my duty to say here at once that a consumptive person should never marry. All mothers know, or ought to know, that consumption is caused by a particular sort of matter called tubercle which, by way of getting rid of it perhaps, Nature deposits in, say, the lungs of the young person. This acts like a foreign body; that is, it may lie quiescent for a long time, and as the child gets stronger, it may even be absorbed, but if she catches cold, that wicked little lump of deposit is sought out and, becoming inflamed, sets up mischief all around. It is coughed up, but leaves an ulcer, and this forms a cavity, after which the end is not far distant. But consumption in children, or the young either, is more often caused by the deposit of tubercle in other parts of the body, especially in the glands. Now, the probability being that I shall devote a whole article to a consideration of consumption, I need not do more here than generalise and give a few words of good advice. I think, mater, that if this advice proves of service to you and gives you hope, this health sermon shall not have been written in vain. “I’m afraid that my lassie is dwining,” said a Scottish mother to me once. “What think you, doctor?” I was only a very young fellow then, but had inherited a modicum of common sense from most intelligent parents, so I took Mary in hand.