Word Study
    pentamethylene
CIDE DICTIONARY
pentamethylene, n. [Penta- + methylene.]. 
                                            
                                         A hypothetical hydrocarbon, C5H10 , metameric with the amylenes, and the nucleus of a large number of derivatives; -- so named because regarded as composed of five methylene residues.  Cf. Trimethylene, and Tetramethylene.                                                                                 [1913 Webster]                                                                                                                    
                                                                                    
            For further exploring for "pentamethylene" in Webster Dictionary Online
        


 
    
 
