Exposed to the action of the air, the muscular texture is affected in two ways. 1st. It dries, if cut into thin slices, admitting of the evaporation of the fluids it contains. Then its appearance is of a dull brown; its fibres contract, it becomes thinner, hard and brittle. If replunged into water within some days, even fifteen or thirty after its drying, it resumes its primitive softness and form, and has a less deep coloured tinge. The water that has been used for this softening is more or less fetid, and similar to that of macerations. 2d. Exposed in too great a mass to the air, the muscular texture does not dry, but becomes putrid. Thus in making anatomical preparations by drying, care should be taken to lessen the thickness of the fleshy parts, or to arrange them so that the air can penetrate them everywhere. Putrefaction is inevitable if the air is moist, if the evaporation of the fluids is not quick enough to produce drying. When it becomes putrid, the muscle assumes a green, livid colour; it exhales an offensive odour. Under the influence of the same circumstances it becomes putrid much quicker than the fibrous, the cartilaginous and the fibro-cartilaginous systems. The odour that it exhales then is also very different from that of these systems; a phosphoric light often escapes from it. A mass of putridity, in which all the fibres have almost disappeared, takes the place of the muscle, when putrefaction is advanced. This mass of putridity gradually evaporates in part, and there remains a dark brown residue, which dries and becomes hard and brittle, nearly like the muscle dried in the ordinary state, though the appearance however may be very different.