120 ADIPOCIRE. OLEIC ACID. 



Adipocire. When animal (proteid) tissues are buried for some time 

 in damp ground or otherwise exposed to moisture in the absence of any 

 free supply of oxygen they are frequently found to have undergone a 

 peculiar change by which they are converted into a waxy or fatty 

 substance. This is known as adipocire. It consists not of true neutral 

 fats but of the ammonium, and in some cases calcium, salts of the 

 highest fatty acids palmitic and stearic, or of the free acids themselves 1 . 

 Practically nothing is definitely known as to the agencies and mode of 

 this conversion. It may be the result of a purely chemical change or 

 perhaps it is more probably due to the action of some micro-organism 2 . 

 On either view of its formation the occurrence of adipocire is of extreme 

 interest as showing a possible direct formation of the higher fatty acids 

 and hence of fats from proteids. It is however supposed by some 

 authors that the adipocire is formed entirely by change and aggrega- 

 tion from the fats present in the tissues at death 3 . This view is 

 probably incorrect. 



II. ACIDS OF THE OLEIC (ACRYLIC) SERIES. CJELj^ . COOH 

 (monobasic). 



The acids of this series bear the same relationship to the olefines 

 (C 2 H 4 ) that those of the acetic do to the paraffins (CH 4 ). Some of the 

 higher members of the series are found as glycerin compounds in 

 various fats. 



They bear an interesting relation to the acids of the acetic series, 

 breaking up when heated with caustic potash into acetic acid and 

 some other member of the same series : thus, 



Oleic acid. Potassium acetate. Potassium palmitate. 



- KC 2 H 3 2 + KC 16 H 31 O 2 + H 2 . 



Oleic acid. C^H^COOH. 



This is the only acid of the series which is physiologically important. 

 It is found united with glycerin in all the fats of the human body. 



When pure it is, at ordinary temperatures, a colourless, odourless, 

 tasteless, oily liquid, solidifying at 4C. to a crystalline mass. In- 

 soluble in water, it is soluble in alcohol and in ether. It cannot be 

 distilled without decomposition. It readily forms with potassium and 

 sodium hydroxide, soaps which are soluble in water : its compounds 



1 Ebert, Ber. d. d. chem. Gesell Bd. vm. (1875), S. 775. 



2 Kratter, Zt. f. Biol. Bd. xvi. (1880), S. 455. Lehmann, Sitzb. d. phys.-med. 

 Gesell. Wiirzburg, 1888, S. 19. 



3 Zillner, Viertelj. f. ger. Med. u. off. Sanitatsw. (N.F.), Bd. XLIV. (1885), S. 1. 



