414 RETROGRESSIVE CHANGES 



diffusion of the ammonium soaps formed during the decomposition. 

 As the subcutaneous fat is hardened by the formation of soaps, and the 

 bones remain to hold the parts in position, the general form of the 

 body is preserved, creating the impression that its entire substance has 

 been converted into adipocere, when the total mass may actually 

 weigh but twenty pounds or so, and, according to Zillner's estimate, 

 not more than one-tenth of the muscle substance is replaced by adi- 

 pocere. This false impression is probably responsible for much of the 

 mistaken idea concerning the conversion of tissue proteins into fatty 

 acids. Thus, Schmidt^'' found that in early Egyptian mummies 60 

 per cent, of the weight of the lungs and 30 per cent, of the spleen con- 

 sisted of fatty acids, and fell into the usual error of considering this 

 conclusive evidence of transformation of proteins into fat. 



Numerous attempts have been made to prove that muscle could 

 be thus converted into fatty acids and soaps, but although success has 

 been claimed by a few, the results are not entirely convincing. ^^ 

 Bacteria can convert proteins into fats, beyond a doubt, and they 

 may do so to some slight extent in adipocere formation, but probably 

 this factor is not important. 



In the light of our present conception of fat metabohsm it is prob- 

 able that the process of adipocere formation occurs as follows: The 

 fatty acids of the fat tissue are combined by the ammonia formed 

 during putrefaction, removing these fatty acids from the normal 

 balance of fat and fatty acids in the fat tissue; as a result, the lipase 

 of the fat tissue continues to split the fat, and more fatty acids are 

 produced, which likewise go to form soaps. This continues until 

 practically all the neutral fat has been decomposed, the glycerol dif- 

 fusing rapidly away. The soluble soaps, which the bacteria do not 

 attack, diffuse into the softened muscle tissue, which they gradually 

 replace in part. In the meantime, from the more soluble ammonium 

 soaps, calcium and magnesium soaps are being slowly formed, accord- 

 ing to the usual rule of double decomposition (that the least soluble 

 salt will be formed under such conditions) ; or else, if an acid reaction 

 develops, free fatty acids are precipitated. The oleic acid seems to be 

 converted into the higher fatty acids (Salkowski).-""* It is also possible 

 that the saponification is due to the gradual action of the alkaline 

 fluids produced in decomposition of the tissues, or to the alkalinity 

 of the water in which the body lies. Possibly bacteria may be re- 

 sponsible for this decomposition of the fats rather than the body 

 lipase, for Eijkman^^ has observed that certain bacteria growing in 

 fat-containing agar produce calcium, ammonium, and sodium soa[is, 

 simulating adipocere. ^'^ 



" Zeit. allg. Physiol., 1907 (7), 3G9. 



" See Rosenfeld, Ergcb. dor. Physiol., Abt. 1, 1902 (1), 659. 

 " Festschr. f. Virchow, 1S91, p. 23; corroliorated by Schiitze. 

 "Cent. f. Bakt., 1901 (29), 847. 



«»See also Ccvidalli, \'it>rteljahrschr. froiifhtl. Mod., 190G (32), 219; and 

 Schiitze, Arch. Ilyg., 1912 (70), 110. 





