"Harold," said Ernest Carnegie to his twin-brother at breakfast one morning, "have you got a tooth aching slightly to-day?"

"Yes, by Jove, I have!" Harold answered, laying down the Times, and looking across the table with interest to his brother; "which one was yours?"

"The third from the canine on the upper left side," Ernest replied quickly. "And yours?"

"Let me see. This is the canine, isn\'t it? One, two, three; yes. The same, of course. It\'s really a very singular coincidence. How about the time? Was that as usual?"

"I\'ll tell you in a minute. Mine came on the day of the Guthries\' hop. I was down at Brighton that morning. What date? Let me think; why, the 9th, I\'m certain. To-day\'s what, mother?"

"The 23rd," said Harold, glancing for confirmation at the paper. "The law works itself out once more as regularly as if by machinery. I\'m just a fortnight later than you, Ernest, as always."

Ernest drummed upon the table with his finger for a minute. "I\'m afraid you\'ll have it rather badly to-day, Harold," he said, after a pause. "Mine got unbearable[Pg 129] towards midday, and if I hadn\'t had it looked to in the afternoon, I couldn\'t have danced a single dance to save my life that evening. I advise you to go round to the dentist\'s immediately, and try to get it stopped before it goes any further."

Harold finished his cup of coffee, and looked out of the window blankly at the fog outside. "It\'s an awful thought," he said at last, "this living, as we two do, by clockwork! Everybody else lives exactly the same way, but they don\'t have their attention called to it, as we do. Just to think that from the day you and I were born, Ernest, it was written in the very fabric of our constitutions that when we were twenty-three years and five months old, the third molar in our upper left jaws should begin to fail us! It\'s really appalling in its unanswerable physical fatalism, when ones comes to think upon it."

"So I said to myself at the Guthries\', the morning it began to give me a twinge," said Ernest, in the self-same tone. "It seemed to me such a terrible idea that in a fortnight\'s time, as certain as the sun, the very same tooth in your head would begin to go, as the one that was going in mine. It\'s too appalling, really."

"But do you actually mean to say," asked pretty little Nellie Holt, the visitor, newly come the day before from Cheshire, "that whenever one of you gets a toothache, the other one gets a toothache in the same tooth a fortnight later?"

"Not a toothache only," Ernest answered—he was studying for his degree as a physician, and took this department upon himself as by right—"but every other disease or ailment whatsoever. We\'re like two clocks wound up to strike at fixed moments; only, we\'re not wound up to strike exactly together. I\'m fourteen days in advance of Harold, so to speak, and whatever happens to me to-day will happen to him, in all probability, exactly a fortnight later."[Pg 130]

"How very extraordinary!" said Nellie, looking quickly, from one handsome clear-cut face to its exact counterpart in the other. "And yet not so extraordinary, after all,—when one comes to think how very much alike you both are."

"Ah, that\'s not all," said Ernest, slowly; "it\'s something that goes a good deal deeper than that, Miss Holt. Consider that every one of us is born with a certain fixed and recognizable constitution, which we inherit from our fathers and mothers. In us, from our birth upward, are the seeds of certain diseases, the possibilities of certain actions and achievements. One man is born with hereditary consumption; another man with hereditary scrofula; a third with hereditary genius or hereditary drunkenness, each equally innate in the very threads and strands of his system. And it\'s all bound to come out, sooner or later, in its own due and appointed time. Here\'s a fellow whose father had gout at forty: he\'s born with such a constitution that, as the hands on his life-dial reach forty, out comes the gout in his feet, wherever he may be, as certain as fate. It\'s horrible to think of, but it\'s the truth, and there\'s no good in disguising it."

Nellie Holt shuddered slightly. "What a dreadful materialistic creed, Mr. Carnegie," she said, looking at him with a half-frightened air. "It\'s almost as bad as Mohammedan fatalism."

"No, not so bad as that," Ernest Carnegie answered; "not nearly so bad as that. The Oriental belief holds that powers above you compel your life against your will: we modern scientific thinkers only hold that your own inborn constitution determines your whole life for you, will included. But whether we like it or dislike it, Miss Holt, there are the facts, and nobody can deny them. If you\'d lived with a twin-sister, as Harold and I have lived together for twenty-three years, you\'d see that the clocks go as they are set, with fixed and predestined regularity.[Pg 131] Twins, you know, are almost exactly alike in all things, and in the absolute coincidence of their constitutions you can see the inexorable march of disease, and the inexorable unfolding of the predetermined life-history far better than in any other conceivable case. I\'m a scientific man myself, you see, and I have such an opportunity of watching it all as no other man ever yet had before me."

"My dear," said Mrs. Carnegie, the mother, from the head of the table, "you\'ve no idea how curiously their two lives have always resembled one other. When they were babies, they were so much alike that we had to tie red and blue ribbons round their necks to distinguish them. Ernest was red and Harold blue—no, Ernest was blue and Harold red: at least, I\'m not quite certain which way it was, but I know we have a note of it in the family Bible, for Mr. Carnegie made it at the time for fear we should get confused between them when we were bathing them. So we put the ribbons on the moment they were christened, and never took them both off together for a second, even to bathe them, so as to prevent accidents. Well, do you know, dear, from the time they were babies, they were always alike in everything; but Ernest was always a fortnight before Harold. He said "Mamma" one day, and just a fortnight later Harold said the very same word. Then Ernest said "sugar," and so did Harold in another fortnight. Ernest began to toddle a fortnight the earliest. They took the whooping cough and the measles in the same order; and they cut all their teeth so, too, the same teeth first on each side, and just at a fortnight\'s distance from one another. It\'s really quite an extraordinary coincidence."

"The real difficulty would be," said Harold, "to find anything in which we didn\'t exactly resemble one another. Well, now I must be off to this horrid office with the Pater. Are you ready, Pater? I\'ll call in at Estwood\'s in the course of the morning, Ernest, and tell him to look[Pg 132] after my teeth. I don\'t want to miss the Balfours\' party this evening. Curious that we should be going to a party this evening too. That isn\'t fated in our constitutions, anyhow, is it, Ernest? Good morning, Miss Holt; the first waltz, remember. Come along, Pater." And he went out, followed immediately by his father.

"I must be going too," said Ernest, looking at his watch; "I have an appointment with Dowson at Guy\'s at half-past ten—a very interesting case: hereditary cataract; three brothers, all of them get it, each as he reaches twelve years old, and Dowson has performed the operation on two, and is going to perform it on the other this very day. G............