But when we learn the condition necessary that a body which has once been reduced to the state of passive efficiency should be restored to active life, we recognise that even when science has learned how to reduce vitality to a minimum without destroying it, few will care to risk the process, either in their own persons or in the case of those dear to them. Besides the condition already indicated, that the muscular irritability and the nervous excitation must be simultaneously and equally reduced, it is essential that the blood, the muscular fluid, and the nervous fluid should all three remain in what Dr. Richardson calls the aqueous condition, and not become what he calls pectous, a word which we must understand to bear the same relation to the word solid or crystalline that the word "aqueous," as used by Dr. Richardson, bears to the word watery. If all three fluids remain in the aqueous condition, "the period during which life may be restored is left undefined. It may be a very long period, including weeks, and possibly months, granting that decomposition of the tissues is not established; and even after a limited process of decomposition, there may be renewal of life in cold-blooded animals. But if pectous change begins in any one of the structures I have named, it extends like a crystallization quickly through all the structures, and thereupon recovery is impossible, for the change in one of the parts is sufficient to prevent the restoration of all. Thus the heart may be beating, but the blood being pectous it beats in vain; or the heart may beat and the blood may flow, but the voluntary muscles being pectous the circulating action is vain; or the heart may beat, the blood may flow, and the muscles may remain in the aqueous condition, but the nerves being pectous the circulating action is in vain; or sometimes the heart may come to rest, and the other parts may remain susceptible, but the motion of the heart and blood not being present to quicken them into activity, their life is in vain." Add to this, that the restoration of the motor forces, of the muscular irritability, and of the nervous excitation, must be as simultaneous and as equal as their reduction had been, and we begin to recognise decided objections to the too frequent suspension of animation, even when the most perfect artificial means have been devised for bringing about that interesting result. Although, however, we may not feel encouraged to believe that many will care to have experiments tried on themselves in this direction, we may still examine with interest the results of experimental research and experience. These agree in showing that there are means by which active life may be suspended, while at the same time the aqueous condition of the fluids mentioned above (the blood, the muscular fluid, and the nervous fluid, the two latter of which are for convenience called the colloidal animal fluids, and are derived from the blood) is retained.