In one of these early contests one of the combatants, who had armed himself with an exceptionally heavy bludgeon, chanced to strike his antagonist an awful blow on the temple. The result was equally awful. Instead of falling to the ground, stunned by the force of the blow, as had been the usual result under similar circumstances in many previous encounters, the man who had received it simply vanished—instantaneously vanished. Not a trace of him was left, and the Hesperian Cain stood staring at the vacancy which his departed brother had filled, gasping with amazement and consternation at the work he had achieved. As years went on many similar cases occurred. Occasionally this evanescence took place as the result of an accident; the co-operation of a neighbour, though a common, was not an indispensable antecedent. For instance, if a man fell over a precipice several hundred feet high—and many such are to be found among the mountains—evanescence on reaching the foot of it was invariable. At length, by the process of comparing a vast number of instances in which this strange phenomenon had been observed, what was called the Law of Evanescence was established, namely, that a certain class of bodily injuries exist, which result in the instantaneous dissolution and disappearance of the recipient. And here I found my medical education of great service in enabling me to understand the nature of this law; for, from the accounts I got of the various causes of evanescence, it became quite clear to me that in _almost_ every case of the occurrence of the phenomenon, what would be called in human beings a mortal lesion is the invariable antecedent; that, in fact, the decomposition of the body, which on the earth takes place slowly, is instantaneously effected in Hesperos. Having referred to my medical education, I may call the reader’s attention, just in passing, to a difficulty which that education brought very forcibly before my mind. How could there be any science of anatomy in Hesperos? No corpses could be procured for dissection. An amputated arm or leg might be anatomised, but an examination of the structure of any of the vital organs is simply impossible. Just as, in mediæval times, medical students on the earth were obliged to have recourse to the dissection of the lower mammalia, in order to learn their business, so is it now with the Hesperians; and, in both cases, the results arrived at may be useful as the grounds for more or less ingenious hypotheses, but are quite insufficient as a foundation for any science worthy of the name.