The book "Essay on Parkinson's disease" by the famous English doctor James Parkinson is the first attempt to systematically describe the neurodegenerative disease, which later received the name Parkinson's disease. In this essay, the author describes the symptoms, course and consequences of this disease based on his own practical experience. The book provided initial data for further research in the field of neurology and neurological diseases. "Essay on Parkinson's disease" remains a relevant source for the study and understanding of this pathological condition, and also influenced the development of clinical medicine and neuroscience in general.