FATS AND^ RELATED SUBSTANCES. 55 



This may be readily shown by dissolving some fat in a proper 

 solvent which is then allowed to evaporate slowly. 



The common fats can not be distilled under the ordinary 

 pressure without decomposition, and the distillation of the 



FIG. 4. Mutton tallow crystal- FIG. 5. Cat fat crystallized from 

 lized from chloroform. 300 diam- chloroform. 300 diameters, 



eters. 



FIG. 6. Beef tallow crystal- FIG. 7. Beef tallow crystal- 



lized from chloroform. 300 diam- lized from chloroform. 300 diam- 

 eters, eters. 



fatty acids is also difficult. When the common fats are 

 strongly heated they emit a peculiar odor, due to the acrolein 

 formed by the partial destruction of glycerol. The following 

 experiments illustrate some of the points referred to : 



