But the above account of evanescence as, in all cases, the result of mortal lesion, is not in absolute conformity with the facts of experience. Such lesions are unquestionably, in the vast majority of instances, the real causes of the phenomena. Still, occasionally, though comparatively rarely, cases occur which seem to be irreducible to any such rule, and these, for many ages, were regarded as inexplicable anomalies. However, the law which governs such mysterious cases of evanescence was at last found out, as I shall now proceed to explain. This important discovery was really the result of the invention of a most ingenious instrument, by means of which the degrees of pain and suffering on the one hand, and of joy and satisfaction on the other, endured or enjoyed by any given individual, during any assigned period, may be accurately measured, their aggregate amount computed, and the balance on either side struck. The machine is constructed somewhat on the principle of Mr. Fahrenheit’s thermometer, but the details of the construction, and of the mode of fixing the unit on which the calculations rest, were not communicated to me; indeed, the Hesperian who gave me a general account of it very frankly assured me—and I find no difficulty in believing him—that to understand its mode of action lies far beyond the range of my merely human faculties. However this may be, it is not easy to see how, without some such invention, the Second Law of Evanescence could have been discovered; but, by the application of this wonderful instrument to a great number of cases, the Law in question was at last established on a sufficiently wide inductive basis. This Second Law of Evanescence may be stated in a popular form as follows:—Evanescence takes place whenever the total quantity of suffering undergone by anyone, exceeds, by a certain fixed amount, the total quantity of happiness he has enjoyed. This fixed amount when estimated by the Hesperian joy-and-sorrow-metronome, above described, is exactly ten million units of its scale. When this negative balance is reached, the second law acts spontaneously, and the sufferer is thus released from all further misery. Under the existing conditions of life in Hesperos, it would be hard to over-estimate the importance of this law. For example, only for it there is nothing to prevent a court of justice from sentencing a prisoner to eternal punishment. And, as a matter of fact, one of the very earliest noticed cases of anomalous evanescence was the result of just such a sentence.