Parsons
Discovery : Steam Turbine

Pascal
Discoveries : Adding Machine, Calculating Machine

Paul Ehrlich
Discovery : Chemotherapy

Paul Gyorgy
Discovery : Vitamin B6

Pavlov
Discovery : Theory Of Conditioned Reflex

Peter Goldmark
Discovery : The Long Playing Microgroove Record

Pierre Simon De Laplace
Discovery : Newtonian Mechanics

Plastic Carothers
Discovery : Nylon

Plimsoll
Discovery : Line Of Demarcation (Ship)

Priestley
Discoveries : Laughing Gas, Oxygen

Paints : Shalimar
Paper clip : Johann Vaaler
Parking meter : Carlton Mcgee
Penicillin : Alexander Fleming
Periodic Law : Mendeleef
Periodic Table of Elements : Dmitri Mendeleev
Pharmacology Gertrude : Belle Elion
Phonograph : Edison
Photograph : Dauguerre
Photography (paper) : W.H. Fox Tablot
Phototherapy : N.R.Finsen
Pneumatic Tyres : John Boyd Dunlop
Positive Electrons : Anderson
Power Loom : Edmund Cartwright
Powerloom : Cartwright
Principle for lever : (S.P.Gravity) Archimedes
Printing for the Blind : Braille
Printing Press : Johannes Gutenberg
Psycho-analysis : Dr.Sigmund Freud
Psychology of the Unconscious : Sigmund Freud