The _Skin_ is the exterior investment of the body, which it serves to cover and protect. It is continuous at the aperture of the internal cavities with the lining membrane of those cavities, the internal skin or mucous membrane, and is composed essentially of two layers—derma and epidermis. The derma or cutis is chiefly composed of areola-fibrous tissues, besides which it has entering in its structure elastic tissues and smooth muscular fibre, together with blood vessels and nerves. The epidermis or cuticle (scarf-skin) is a product of the derma, which it serves to envelop and defend. That surface of the epidermis which is exposed to the influence of the atmosphere and exterior sources of injury is hard and horny in texture, while that which lies in contact with the under layer is soft and cellular. _Viscera._—The viscera of the human body are situated in the three great cavities—cranio-spinal, thorax and abdomen. The viscera of the cranio-spinal cavity are the brain, with the spinal cord, and the principal organs of sense. The viscera of the chest are, the central organs of circulation, the heart, the organs of respiration, the lungs. The abdominal viscera admit of a sub-division into those which properly belong to that cavity, viz.: the alimentary canal, the liver, pancreas, spleen and kidneys; and those of the pelvis, the bladder and the internal organs of generation. _Cartilage._—In the structure of joints, cartilages serve the double purpose of a connecting and separating medium; in the former capacity possessing great strength; in the latter, smoothness and elasticity. For instance, the costal cartilages unite the ribs with the sternum and form the point of separation by the knife, when it is desired to raise the sternum, as in the preceding process of embalming. _Gall Bladder_ is the reservoir of the bile; it is a sac situated in a fosse on the under surface of the right lobe of the liver. _Pancreas._—It is a long, flattened, conglomerate gland; it is about six inches in length, and is situated transversely across the posterior wall of the abdomen and behind the stomach. _Supra-Renal Capsules_ are two small, yellowish and flattened bodies surmounting the kidneys, and inclining inwards and towards the vertebral column. _Kidneys_ are the secreting organs of the urine; they are situated in the lumbar region, and at each side of the vertebral column. _Pelvis._—The cavity of the pelvis is that portion of the great abdominal cavity which is included between the bones of the pelvis. The viscera of the pelvis in the male are the urinary bladder, prostrate gland and rectum. _Bladder._—It is a hollow, membranous viscus, triangular and flattened against the pubes when empty, ovoid when distended, and in front of and upon the rectum.