midnight
`` I have , my lord count ; I may say there are few that are not known to Father Aldrovani . I have spent many years in research . '' `` Indeed ! '' `` Yes ; the midnight lamp has burned till the glorious sun has reached the horizon , and brings back the day , and yet have I been found beside my books . '' '' 'T is well ; men like you should well know the value of the purest and most valuable metals the earth produces ? '' `` I know of but one -- that is gold ! '' '' 'T is what I mean . ''