392 RETROGRESSIVE CHANGES 



acid crystals, and Schwartz and Kayser*^ ascribe their formation to 

 the action of lipolytic staphylococci. 



If the necrotic tissue is in contact with living tissue over a con- 

 siderable area, enough of these products of autolysis and putrefaction 

 may be absorbed to cause intoxication (sapremia). At the same time, 

 the formation of such large quantities of crystalloids from the pro- 

 teins of the dead tissue leads to a diffusion of water into this area, 

 with consequent swelling, and often a lifting up of the skin in the 

 form of blisters. 



Emphysematous gangrene, ^^ usually produced by gas-forming an- 

 aerobic bacteria, including B. aerogenes capsulatus, may also possibly 

 be produced by B. coli communis in diabetic patients in whose blood 

 and tissues there may occur sufficient sugar to permit of gas-formation. 

 Hitschmann and Lindenthal found that the gas produced in cultures 

 by an anaerobic organism which they isolated fi'om a case of 

 emphysematous gangrene, consisted of 67.55 per cent, hydrogen, 

 30.62 per cent, carbon dioxide, and traces of ammonia and nitrogen; 

 this corresponds to the statement of Welch and Nuttall that the gas 

 in the tissues of infected animals is inflammable. Dunham^^ found 

 that the gas produced by B. aerogenes capsulatus in cultures has the 

 following composition: Hydrogen, 64.3 per cent.; carbon dioxide, 

 27.6 per cent.; other gases, probably chiefly nitrogen, 8.1 per cent. 

 Grown in a medium of muscle and water. Wolf ^° found 70-75 per cent 

 of CO2 produced by B. sporogeiies, while B. Welchii produced 38 per 

 cent, of CO2, the rest being chiefly H. The former bacillus is very 

 actively proteolytic, the latter less so. Organisms of this group pro- 

 duce much volatile organic acid which is probably an important factor 

 in the local necrosis, especially in producing a negative chemotaxis; 

 it may also contribute to the acidosis of the disease. ^^ 



RIGOR MORTIS 



This topic may be appropriately considered in connection with cell 

 death, since it is a characteristic change occurring after general 

 death. All forms of muscle, striped, smooth, and cardiac, undergo 

 this change, which is shown by a shortening and thickening of the 

 muscle, which also becomes opaque and hard. Rigor mortis begins 

 first in the heart muscle, according to Fuchs,^^ but it is generally 

 observed first in the eyelids, then in the muscles of the jaw, from 

 which point it proceeds downward, although the upper extremities 



*' Zeit. klin. Med., 1905 (56), 111. 



"« Complete literature by Weinberg and S^guin, "La Gangrene gazeuse," Paris, 

 1918. 



"Johns Hopkins Hosp. Bull., 1897 (8), 68. 



60 Jour. Path. Pact., 1919 (22), 270. 



61 Wrifrht and Fleming, Lancet, 1918 (i), 205. 



62 Literature, see v. Furth, Ilandhuch d. Biochem., 1909 (II (2), 252; also 

 Meltzcr and Auer, Jour. E.xp. Med., 190S (10), 45). 



"Zeit. f. Ileilk., 1900 (21, Path. Abt.), 1. 



