[2] Merritt's influential contributions to neurology included the discovery of the anticonvulsant properties of phenytoin (Dilantin) in 1938, alongside Tracy Putnam.
According to Goodman and Gilman's Pharmacological Basis of Therapeutics: In contrast to the earlier accidental discovery of the antiseizure properties of potassium bromide and phenobarbital, phenytoin was the product of a search among nonsedative structural relatives of phenobarbital for agents capable of suppressing electroshock convulsions in laboratory animals.
His early work on the normal properties of the cerebrospinal fluid (CSF) was updated and published by one of his students, Robert Fishman, in a text that is the acknowledged standard on the topic.
Merritt was also known in his day as an expert on neurosyphilis; his 1946 monograph on the topic provided an overview of this condition, which almost disappeared from the medical eye shortly thereafter owing to the advent of penicillin.
Merritt died in 1979 from complications of cerebrovascular disease and normal pressure hydrocephalus; ironically, the latter condition was a syndrome whose existence he had never fully accepted during his career.