 In criminal cases he drew public attention to himself by his cross-examination in the Bravo case in 1875, and from that time onward was connected with most criminal "causes célèbres," being conspicuous in the prosecution of fraudulent persons like Madame Rachel and Slade the medium.Among other cases may be mentioned the Hatton Garden diamond robbery case; Belt versus Lawes; and the Royal Baccarat Scandal, in which the Prince of Wales was called as a witness; and he was selected by the Parnell Commission to conduct the case for Charles Stewart Parnell and the Irish party against "The Times".Lewis had by far the largest practise in financial cases of any lawyer in London, and was especially expert in libel cases, being retained by some of the chief newspapers.