Possible Clues:

• Half of the Nobel Prize winners, typically
• They put things to the test, as their interest is in most of 15 across
• Brains -- two found in Henry Purcell
• Its scent is different to those working in experimental field
• Biologists, say, analysed insect's bits, taking out book
• Small insect -- it's amazing for biologists, perhaps
• They study the universe of insects -- it's weird!
• Its scent is awful to those working in experimental field
• “____ differ from ordinary mortals by their ability to admire loquacious and complicated delusions” (Anatole France)
• Insects sit (anag.)