The oft-repeated claim that Carl Maria von Weber considered the chromatic bass line in the coda of the first movement evidence that Beethoven was "ripe for the madhouse", seems to have been the invention of Beethoven's first biographer, Anton Schindler . His possessive adulation of Beethoven is well-known, and he was criticised by his contemporaries for his obsessive attacks on Weber. According to John Warrack , Weber's biographer, Schindler was characteristically evasive when defending Beethoven, and there is "no shred of concrete evidence" that Weber ever made the remark. 
Like any traditional Scherzo, Abraham  explains that this too has a Trio section that begins at measure 218 (rehearsal letter D). This starts out in E-flat major with an apparently new and distinctive trumpet melody (the timpani reinforcing the rhythm), though quickly changes to B major (bassoon and horns). This section is characterized by this new melodic material, which develops what was heard earlier and is also closely related to material from the A-group. This section can also be considered developmental space as this melody is passed around the orchestra in a quasi-fugal manner. Other musicologists [ weasel words ] have analysed these Scherzo and Trio sections very differently.