Laws of Cricket 1947 Code (Fourth Edition) - Law 35
The Striker is out "Caught" - If the ball, from a stroke of the bat or of the hand holding the bat, but not the wrist, be held by a Fieldsman before it touch the ground, although it be hugged to the body of the catcher, or be accidentally lodged in his dress. The Fieldsman must have both his feet entirely within the playing area at the instant the catch is completed.
Experimental Law 35 - Caught
The Striker is out "Caught" - If the ball, from a stroke of the bat or off a hand holding the bat, but not the wrist, be held by a Fieldsman before it touch the ground, although it be hugged to the body by the catcher, or be accidentally lodged in his dress. The Fieldsman must have no part of his body grounded outside the playing area in the act of making the catch and afterwards.
Notes on Law 35
1. Provided the ball does not touch the ground, the hand holding it may do so in effecting the catch.
2. The umpire is justified in disregarding the fact that the ball has touched the ground, or has been carried over the boundary provided that a catch has in fact been completed prior to such occurrence.
3. The fact that a ball has touched the striker's person before or after touching his bat does not invalidate a catch.
4. The striker may be "Caught" even if the fieldsman has not touched the ball with his hands, including the case of a ball lodging in the wicket-keeper's pads.
5. A fieldsman standing within the playing area may lean against the boundary to catch a ball, and this may be done even if the ball has passed over the boundary.
6. If the striker lawfully plays the ball a second time he may be out under this Law, but only if the ball has not touched the ground since being first struck.
7. The striker may be caught off any obstruction within the playing area provided it has not previously been decided on as a boundary.
Reproduction of the Laws of Cricket is by kind permission of Marylebone Cricket Club