91648
In 1873 , Frederick Guthrie observed that a grounded , white hot metal ball brought in close proximity to an electroscope would discharge a positively charged electroscope , but not a negatively charged electroscope .
 person: Frederick Guthrie
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Frederick Guthrie 
Answer:
 person: Frederick Guthrie