The canister had no label, and like most substances, it wasn't obvious from sight alone what it was. He could have been a conman, and it seemed most likely. Not many honest people kept unlabelled canisters alongside valueless items.
"What is it?" he managed, giving the item a look over. "It is important that I get the correct substance. I need to be able to synthesise more of it. It is imperative that my patients receive the correct treatment."