law: Indian Evidence Act, 1872 
  21. Proof of admissions against persons making them, and
  
  by or on their behalf
  Admissions are
  
  relevant and may be proved as against the person who makes them, or his
  
  representative in interest; but they cannot be proved by or on behalf of the
  
  person who makes them or by his representative in interest, except in the
  
  following cases:-
  (1) An admission may
  
  be proved by or on behalf of the person making it, when it is of such a nature
  
  that, if the person making it were dead, it would be relevant as between third
  
  persons under section 32.
  (2) An admission may
  
  be proved by or on behalf of the person making it, when it consists of a
  
  statement of the existence of any state of mind of body, relevant or in issue,
  
  made at or about the time when such state of mind or body  existed, and is
  
  accompanied by conduct rendering its falsehood improbable.
  (3) An admission may
  
  be proved by or on behalf of the person making it, if it is relevant otherwise
  
  than as an admission.
  Illustration
  (a) The question
  
  between A and B is, whether a certain deed is or not forged. A affirms that it
  
  is genuine, B that it is forged.
  A may prove a
  
  statement by B that the deed is genuine, and B may prove a statement by A that
  
  the deed is forged ; but A cannot prove a statement y himself that the deed is
  
  genuine, nor can B prove a statement by himself that the deed is forged.
  (b) A, the Captain of
  
  a ship, is tried for casting her away.
  Evidence is given to
  
  show that the ship was taken out of her proper course.
  A produces a book kept
  
  by him in the ordinary course of his business showing observations alleged to
  
  have been taken by him from day to day, and indicating that the ship was not
  
  taken out of her proper course, A may prove these statements, because they
  
  would be admissible between third parties, if he were dead, under section 32,
  
  clause (2)
  (c) A is accused of a
  
  crime committed by him at Calcutta.
  He produces a letter
  
  written by himself and date at Lahore on that day, and bearing the Lahore post
  
  mark of that day.
  The statement in the
  
  date of the letter is admissible, because, if A were dead, it would be admissible
  
  under section 32, clause (2).
  (d) A is accused of
  
  receiving stolen goods knowing them to be stolen.
  He offers to prove
  
  that he refused to sell them below their value.
  A may prove these
  
  statements, though they are admissions, because they are explanatory of conduct
  
  influenced by facts in issue.
  (e) A is accused of
  
  fraudulently having in his possession counterfeit coin which he knew to be
  
  counterfeit.
  He offers to prove
  
  that he asked a skillful person to examine the coin as he doubted whether it
  
  was counterfeit or not, and that person did examine it and told him it was
  
  genuine.
  A may prove these
  
  facts for the reasons stated in the last preceding illustration.