MATTERS GRAY AND WHITE A Neurologist, His Patients and the Mysteries of the Brain <i> by Russell Martin (Fawcett Crest: $4.95) </i>

This is a readable, well-researched, layman’s chronicle of a year spent with a neurologist and of the variable dysfunctions of the brain and central nervous system.

Russell Martin observes the clinical practice of a neurologist friend. Splitting his time between university hospital and his own office, John Ferrier (not his real name) diagnoses and treats (where possible) such diseases as epilepsy, migraine, multiple sclerosis, meningitis, tumor, stroke and Alzheimer’s, among other imposing ailments.

Martin describes, movingly, the enormous courage of Ferrier’s patients as they receive often difficult news. “Nobody goes to see a neurologist because they’re wondering why everything is so great,” he tells Martin. “This isn’t a party.”