The present civilization of Europe very properly began with the clock, a machine which a monk, afterwards Pope Sylvester II, was supposed to have borrowed from Satan, though he was probably indebted for it to the Saracens. For nearly nine hundred years after his day, the best ingenuity of Italian, German, Swiss, French, and English mechanics was devoted to perfecting this noble creation, and it became at last a part of the civilized man, a sort of additional or supplementary sense. The savage may well be excused for mistaking the watch for a living creature. It could not serve us better, if it were. True, it does not perform its function by its own force, but by a stock of extraneous force which is from time to time put into a little store-house called a spring. Neither does the living creature perform its functions by any other force than that which is developed by the chemical action within it, or the _quasi_ combustion of its food. Its will does but direct the application of its mechanical power. It creates none. You may weigh the animal and all the food it is to consume, and thence calculate the utmost ounce of work, of a given kind, which it can thereafter perform. It may do less, but cannot do more. Having consumed all of its food and part of itself, it dies. Its chemical organs have oxydated or burned up all the combustibles submitted to them, thus developing a definite amount of heat, a part of which, at the dictation of the will, by the mechanism of nerves and muscles, has been converted into mechanical motion. When the chemical function ceases, for the want of materials to act upon, the development of heat ceases. There is no more either to be converted into motion or to maintain the temperature of the body; and self-consumption having already taken the place of self-repair, there is no article left but the _articulus mortis_.