Portions of blood drawn from the veins of healthy persons were subjected to the influence of electricity, which were observed to separate sooner than other portions set by as standard marks, from which it was inferred that the stimulus must have acted on a principle of life, to increase its action. To this inference I shall only offer general objections. In the present state of our knowledge, we know that the blood though apparently homogeneous is resolvable by agents into several parts; its crassamentum is composed of gelatinous fibres and red particles, kept in intimate mixture with the serosity by a combination of concurring circumstances, which being destroyed by the operation of chemical agents the separation is precipitated.[A] [A] See observations on albumen, and some other animal fluids, with remarks on the analysis by electro-chemical decomposition. ――――Philosophical Transactions for 1809:――page 373. The life of the blood has also been inferred from its resistance to a reduction of temperature, similar to that of a fresh egg. In a former part of this work I endeavored to shew the fallacy of such an inference, as the circumstance might arise from its peculiar consistency; but in the case of the blood, its temperature will be maintained sometime during its coagulation, by the latent heat disengaged in its change from the fluid to the denser state. As Mr. John Bell has in a striking manner contrasted the arguments in question from which a vital power has been inferred, I shall take the opportunity of transcribing his own words. “We are informed that a fresh egg in consequence of being alive resists the cold, and is frozen with greater difficulty; but once frozen and thawed again it loses its living principle and power of resisting cold at once. It freezes now at the same temperature with other animal matter, shewing no longer any power of generating heat, or resisting cold. But we are told (by Mr. Hunter) that the blood having a determined period of coagulating, you may during that time freeze the blood and it will thaw again and yet congeal at its proper time, and he tells us he had very cleverly frozen blood during the time of its flowing from the vein, then thawed the cake, and still in due time it coagulated. Now since the egg resists the cold by its living principle, why did it die or lose that principle during its conversion into ice? or rather since the blood coagulated by a living effort, how did it preserve its living principle after being frozen?” This shews that the coagulation of the blood has no relation to a living power, but is rather a characteristic of some dead animal matters.