This book includes two biographical stories - about the chemist Humphrey Davy and the physiologist Ivan Mikhailovich Sechenov. They lived at different times and in different countries and worked in different fields of knowledge. But they are related by a love of science, insatiable thirst in search of truth. Davy showed humanity what the universe is made of. He can be called a hunter for chemical elements. For the first time in the history of science, Ivan Mikhailovich Sechenov dared to open the veil that hid the secret of the human brain. This book will introduce you not only to major scientists, its heroes were interesting people, stubborn in achieving their goal, cheerful and sociable in life.