In the cases of persons, who have been shot through the heart, violent spasmodic action is no unusual phenomenon. When I was a boy, the duel took place, between Rand and Millar, at Dorchester Point, then a locality as solitary, as Hoboken, or the Hebrides. The movements of the parties were observed, and their purposes readily surmised, by the officers, on Castle William; and a barge was immediately despatched, from the fort. Shots were exchanged, between the combatants, while the barge was passing over. Rand fell, wounded through the heart; and, after lying motionless, for a very brief space, was seen to leap into the air several feet, and fall again, upon the earth. No. CLIV. We are living and learning, forever. Life is a court of cassation, where truth sits, as chancellor, daily reversing the most incomparably beautiful decrees of theoretical philosophy. It is not unlikely, that a very interesting volume of 600 pages, folio, might be prepared, to be called the _Mistakes of Science_. The elephant in the moon, and the weighing of the fish have furnished amusement, in their day. Even in our own times, philosophers, of considerable note, have seriously _doubted_ the truth of that incomparable hoax, concerning Sir John Herschell's lunar discoveries. Savans were completely deceived, for a considerable period, by the electrical beatifications of Mr. Bose. One of the most amusing occurrences, upon record, on which occasion, the philosopher, unlike Mr. Bose, was a perfectly honest man, befell the famous mathematical instrument-maker, Mr. Troughton. He became fully possessed, by the idea, that certain persons, a select few, were capable of exerting a magnetic influence, over the needle, by advancing their faces towards it. So far from being common, this power was limited to a very small number. The statements of Mr. Troughton, and his well-established reputation, for integrity, caused the subject to be gravely discussed, by members of the Royal Society. Every individual of the very small number, who possessed this remarkable power--every _medium_--was carefully examined. Collusion seemed utterly impossible. A new theory appeared to be established. Amazement ran through the learned assembly. A careful inquiry was instituted, in relation to the manner of life of these _mediums_, from their youth upwards, their occupations, diet, &c., and some very learned papers would, erelong, have been read, before the Royal Society, if Mr. Troughton himself had not previously made a most fortunate discovery--he discovered, that he wore a wig, constructed with _steel_ springs--such, also, was the case with every other _medium_! The tendency to predicate certainty, of things, manifestly doubtful, is exceedingly common. I fell, recently, into the society of some very intelligent gentlemen, who were _certain_, that Sir John Franklin was lost, irrecoverably lost.