254 



III. CHEMISTRY OF NEUTRAL FATS 



10 II 12 13 14 15 16 17 18 



NUMBER OF CARBON ATOMS IN ACID RADICALS 



Fig. 7. The melting points of the polymorphic forms of the 

 simple glj'cerides.''"^ 



10 12 14 16 18 20 



NUMBER OF CARBON ATOMS IN ACID RADICALS 



Fig. 8. The long x-ray spacings of the 13(1)-, a(II)-, and 7(111)- 

 forms of triglycerides. '*2 



are at 3.65, 4.0, 4.6, and 5.3 A. Considerable variations obtain in the short 

 spacings of the triglycerides of the unsaturated acids. 



b. Symmetrical Mixed Triglycerides. The pioneer work on the sym- 

 metrical mixed triglycerides was carried out by Malkin and Meara,^^*-'^" 

 who conducted a comprehensive study of 20 different synthetic compounds. 



