I shut myself up _tete-a-tete_ with the Colonel, and took care that even old Getchen, my housekeeper, now deceased, should not trouble me during my work. I had substituted for the wearisome lever of the old fashioned air-pumps, a wheel arranged with an eccentric which transformed the circular movement of the axis into the rectilinear movement required by the pistons: the wheel, the eccentric, the connecting rod, and the joints of the apparatus all worked admirably, and enabled me to do everything by myself. The cold did not impede the play of the machine, and the lubricating oil was not gummed: I had refined it myself by a new process founded on the then recent discoveries of the French _savant_ M. Chevreul. Having extended the body on the platform of the air-pump, lowered the receiver and luted the rim, I undertook to submit it gradually to the influence of a dry vacuum and cold. Capsules filled with chloride of calcium were placed around the Colonel to absorb the water which should evaporate from the body, and to promote the desiccation. I certainly found myself in the best possible situation for subjecting the human body to a process of gradual desiccation without sudden interruption of the functions, or disorganization of the tissues or fluids. Seldom had my experiments on rotifers and tardigrades been surrounded with equal chances of success, yet they had always succeeded. But the particular nature of the subject and the special scruples imposed upon my conscience, obliged me to employ a certain number of new conditions, which I had long since, in other connections, foreseen the expediency of. I had taken the pains to arrange an opening at each end of my oval receiver, and fit into it a heavy glass, which enabled me to follow with my eye the effects of the vacuum on the Colonel. I was entirely prevented from shutting the windows of my laboratory, from fear that a too elevated temperature might put an end to the lethargy of the subject, or induce some change in the fluids. If a thaw had come on, all would have been over with my experiment. But the thermometer kept for several days between six and eight degrees below zero, and I was very happy in seeing the lethargic sleep continue, without having to fear congelation of the tissues. I commenced to produce the vacuum with extreme slowness, for fear that the gases distributed through the blood, becoming free on account of the difference of their tension from that of rarified air, might escape in the vessels and so bring on immediate death. Moreover, I watched, every moment, the effects of the vacuum on the intestinal gases, for by expanding inside in proportion as the pressure of the air diminished outside of the body, they could have caused serious disorders. The tissues might not have been entirely ruptured by them, but an internal lesion would have been enough to occasion death in a few hours after reanimation. One observes this quite frequently in animals carelessly desiccated.