_Pathology._—Excessive shrinking and obliteration takes place among the capillaries. The skin becomes diminished in thickness. When this occurs, it is easily seen why in old age there will follow, after the injection of fluid into the arterial system, greenish, brownish, and soft spots, in the different parts of the body, especially notable in the face, neck and hands. The products of degeneration may accumulate in the tissues and cause them to be thicker than they are in health, as is seen in the vessels, the walls of which are much thicker than normal. The blood contains fewer corpuscles and solid constituents, is more watery, and coagulates more readily; also the total quantity is less. The pericardium, endocardium, and the capsules of the liver and spleen are opaque and toughened. Degeneration of the cardiac substance may lead to a state of asthenia, which generally produces death. Dilatation of the orifices of the heart may be the prominent lesion, or they may be contracted by atheroma, or by thickening of the vales or rings. The lungs are changed more or less, increasing the bronchial secretions, which during life have been attended by severe paroxysms of coughing. _Treatment._—Inject half strength fluid for the first bottle, following that with ¾ strength for the second and normal for the third and all thereafter if more be necessary. Blood may be drained from the vein if the operator thinks it advisable. The commercial face solution or water should be used on the face while massaging in order that the skin may be kept moist and to prevent dessication from the action of the fluid. The cavity should be injected as a matter of precaution. =Gangrene.=—_Synonyms._—Senile gangrene; mortification. _Definition._—Putrefactive fermentation of dead tissue, from various causes. _Treatment._—The extremities are affected in senile gangrene. They should be wrapped with absorbent cotton which should then be saturated with fluid. The body itself should receive the same treatment accorded in the paragraph on senility. INDEX (References are to pages.) A. Abdomen, 101, 254 Abdominal cavity, 101, 254 Abdominal fermentation, 182 Abdominal post, 351 Absence of normal moisture in skin, 200 Alimentary canal, 96 Anatomical guides, 225 Anatomy, 33 Angiology, 34 Antemortem staining, 191 Anus, 112 Apnea, 157 Aponeuroses, 55 Appendix, 109 Arterial system, 125 Arteries, structure of, 58 Artery, differentiated from nerve, 215 Artery, differentiated from vein, 215 Artery, how to cut for injection, 216 Artery, how to raise, 214 Artery, selection of, 211 Ascending color, 111 Asphyxia, 157 Axillary artery, location, 231 Aztecs embalming, 19 Azygos system, 125 B.