4095
In 1938 , outside scientists including H. Houston Merritt and Tracy Putnam discovered phenytoin 's usefulness for controlling seizures , without the sedative effects associated with phenobarbital .
 person: H. Houston Merritt; person: Tracy Putnam
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 person: H. Houston Merritt; person: Tracy Putnam