The reason for the unusual purchase — 220 pounds of highly caustic fluorine gas — was never explained, but someone at Iran’s Sharif University was clearly anxious to collect. For months, the mysterious buyer bombarded a British supply company with telexes, demanding to know when his 45 canisters would arrive.

“We have not received your reply,” complained one telex, sent from the Tehran school’s purchasing department and written partly in broken English. “We are awaiting for hearing from you as soon as possible.”