“No more do I, inspector,” Sir Clinton retorted blandly. “I should think New-Skin had nothing whatever to do with it.”
“Then what's the point?” Armadale demanded.
“It's plain enough, if you'd keep your ears open. When I encouraged the constable to babble at large about Peter Hay, I was on the look-out for one thing. I found out that he didn't suffer from asthma.”
“I don't see it yet, sir,” the inspector admitted in perplexity.
Wendover had the information which Armadale lacked.
“Now I see what you're after, Clinton. You're thinking of amyl nitrite—the stuff asthmatics inhale when they get a bad turn? You wanted to know if Peter Hay ever used that as a drug? And, of course, now I come to think of it, that stuff has the pear-drop odour also.”
“That's it, squire. Amyl nitrite for asthma; the solvent that evaporates and leaves the collodion behind when you use New-Skin; and the perfume of pear-drops—they're all derived from a stuff called amyl alcohol; and they all have much the same smell. Eliminate New-Skin, as it doesn't seem to fit into this case. That leaves you with the possibilities that the body smelt of pear-drops or of amyl nitrite.”
Inspector Armadale was plainly out of his depth.
“I don't see that you're much further forward, sir. After all, there are the pear-drops. What's the good of going further? If it's poison you're thinking of—— Is this amyl nitrite poisonous, and you think it might have been used in the pear-drops so that their perfume would cover its smell?”
“It's a bit subtler than that, inspector. Now I admit quite frankly that this is all pure hypothesis; I'm merely trying it out, so to speak, so that we can feel certain we've covered all the possibilities. But here it is, for what it's worth. I'll put it in a nutshell for you. Amyl nitrite, when you inhale it, produces a rush of blood to the brain.”