The Handbook of Soap Manufacture. H. A. Appleton

      Berthelot subsequently confirmed Chevreul's investigations by directly synthesising the fats from fatty acids and glycerol, the method he adopted consisting in heating the fatty acids with glycerol in sealed tubes. Thus, for example:—

      Since glycerol is a trihydric alcohol, i.e., contains three hydroxyl (OH) groups, the hydrogen atoms of which are displaceable by acid radicles, the above reaction may be supposed to take place in three stages. Thus, we may have:—

      There are two possible forms of monoglyceride and diglyceride, according to the relative position of the acid radicle, these being termed alpha and beta respectively, and represented by the following formulæ, where R denotes the acid radicle:—

      Monoglyceride:—