Eliphas Levi 
History of Magic, Including a Clear and Precise Exposition, of Its Procedure, Its Rites and Its Mysteries [PDF ebook] 

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Opus Izz’erarcbicum at catfialz’cum (definition of the Great Work, according to Heinrich Khunrath)