ROLE OF BILE IN LIPID ABSORPTION 



107 



stearic acid-choleic acid; and naphthalene-apocholeic acid, myristic acid- 

 eholeic acid. Desoxycholic and apocholic acids gave a similar unbroken 

 curve. It is believed that this ability to form an unbroken series of mixed 

 crystals indicates that the crystal structures of the different choleic acids 

 are analogous, in spite of the unlike nature of their constituents and the 

 differences in the proportion of the acholic component. 



The x-ray patterns of the various choleic acids composed of the fatty 

 acids from propionic to cerotic acids have been investigated by Kratky 



Adipic Acid 1 00% 90 

 Desonycholie 0% 1 

 Acid 



Fig. 3. Melting point and thawing point diagram of the system adipic acid 

 + desoxycholic acid. 526 The abscissae show molecular percentages, the ordi- 

 nates the melting points (upper curve) and thawing points (lower curve). The 

 melting point of the molecular compound, 3 molecules desoxycholic acid + 1 

 molecule adipic acid, is situated between the melting points of its components. 



and Giacomello. 547 These complexes show identical interference and in- 

 tensity values. It is suggested that the fatty acids are oriented in canals 

 and surrounded by a network of desoxycholic acid. However, this does not 

 explain why no coordination values higher than 8 are found with acids, 

 paraffins, and aralkyl compounds, nor why the polynuclear aromatic hydro- 

 carbons have very low coordination values. More recently, Caglioti and 

 Giacomello 548 and Giacomello alone 549 have investigated the palmitic acid- 



547 O. Kratky and G. Giacomello, Monatsh., 69, 427-436 (1936). 



548 V. Caglioti and G. Giacomello, Gazz. chim. ML, 69, 245-254 (1939). 



549 G. Giacomello, Atti accad. naz. Lincei, Ser. 6, Classe sci. fis. mat e nat., 27, 101-108 

 (1938). 



