Complex sentence: Fairley's proposed use of atabrine as a prophylactic agent was accepted, and it was calculated that Allied requirements for atabrine would be 200 tonnes per annum, of which 50 tonnes would be manufactured in the United Kingdom and 150 tonnes in the United States.
Split into simpler sentences: Fairley's proposed use of atabrine as a prophylactic agent was accepted. It was calculated that Allied requirements for atabrine would be 200 tonnes per annum, of which 50 tonnes would be manufactured in the United Kingdom and 150 tonnes in the United States.