That eggs resist in proportion to their freshness a reduction of temperature, is not in my conception necessarily owing to their vitality; which may be inferred from the circumstance, that as long as they were capable of being hatched, however stale, they must still retain their principle of life, and therefore, a stale egg able to afford a chick by incubation, should freeze no sooner than one newly laid. Another solution of the phenomena can be offered which may have escaped the attention of the ingenious experimenter. In the present state of chemistry, acquainted with the passage of heat through bodies, we know that the change of temperature in a tenacious semifluid must be very slow; caloric passing in such bodies, rather by transposition of particles than by their contact; the heat of the new laid egg is but little below 100° of Fahrenheit and consequently must part with near 70° of heat before it could congeal. And having undergone that change, it would require some time to equalize its temperature with surrounding bodies. If the egg does contain an independent principle of life why is not the chick evolved without the aid of other agents? The last argument I shall notice on this fanciful hypothesis is not least in importance with the advocates for the independent principle but is one on which they place much reliance, viz., the contraction of muscles after removal from the body. There is little doubt that the contractibility of the muscular fibres is variously disposed in different animals and that particular parts may possess more tenacity of action than others; but if it were a constituent principle of the part, it should continue undiminished in power until the texture be entirely destroyed, and not gradually decrease in energy, as is the case, till it cease to act altogether. It may be strongly urged against this hypothesis that stimuli applied to the nerves soon after the death of an animal, produce more violent action than when applied to the muscles themselves; and much sooner destroy their aptitude for action, which fact, has been shewn true, by a series of ingenious and well conducted experiments, entered on by the learned doctor Whytt, of Edinburgh. Hence these propositions which have been displayed with no little triumph by the votaries of an independent life, can afford their opinions no support.