Love is the greatest and most powerful worker of miracles, it is the thaumaturgus of thaumaturgists, and I in the small circle of my experiences know a young man, who has never been able to desire or love a young woman, but adores old women; and if he does not marry any of his venerable friends, it is from fear of ridicule. It is true that in this case we treat of an aberration of sexual instinct to be classed with sodomy and incest; but this _pathological nomad_ is seated in an otherwise normal and perfect brain. Intellectual unions on the other hand are physiological facts which offend no rights of nature, and ought to be respected and studied, as rare, but most noble phenomena of the human heart. With regard to the health of those desiring to take a wife, and the health of our companion, I will recommend to them my _Elementi d’igiene_, and more especially _Igiene d’amore_, where I have fully treated this vital side of the great problem. CHAPTER IV. PHYSICAL SYMPATHIES.—RACE AND NATIONALITY. Love is the strongest, the most irresistible, the most fatal of chemical affinities, and if potassium can extract oxygen from water, unite with it, light it, and make it burn with a bright flame and conflagration, consider the case of a man who first sees a woman and feels that she is precisely the atom with whom it is his irresistible destiny to unite, in order to kindle the flame of life. It is no longer a simple electro-negative molecule which seeks, absorbs, and consumes the opposite electro-positive molecule, but it is an organism, an entire microcosm, which attracts another microcosm on its own vortex, so as to live united in the heaven of life, as two stars above live united in a mysterious and eternal marriage. There are all the cellules of the epidermis, and all the pores of the skin, which seek the cellules and pores of the other organism; there are the inward parts which palpitate, the nerves which vibrate, the feelings which weep and sob, the thoughts that are crowded with all the soul’s expression, and seek those inner parts, nerves, affections, and thoughts, which nature has made kin. Not unjustly was the moment given that applicable French name, _Coup de foudre_. Lightning it is—that gigantic force which draws man and woman together and makes of them one being. In its minor grades we call the force sympathy; a little later, when stronger, we call it love. ⁂ I detest pedantic preachers of prudence, who make it consist of an emasculation of all virility of body and thought; but I also appreciate the need of repeating to you: _Distrust the flashes of lightning!_ Perhaps you will say to me: “That is the same as preaching the doctrine: do not believe in hunger, thirst, or sleep.”