You're sure to be asked about cacodyl.

Tester's dead on it.

He asks every one how it is prepared." Tom, much perturbed at these tidings, was feverishly endeavouring to extract some little information from his companion concerning the compound, when a bell rang abruptly inside the room and a janitor with a red face and a blue slip of paper appeared at the door.
"Dillon, Dimsdale, Douglas," this functionary shouted in a very pompous voice, and three unhappy young men filed through the half-opened door into the solemn hall beyond.
The scene inside was not calculated to put them at their ease.

Three tables, half a dozen yards from each other, were littered with various specimens and scientific instruments, and behind each sat two elderly gentlemen, stern-faced and critical.

At one side were stuffed specimens of various small beasts, numerous skeletons and skulls, large jars containing fish and reptiles preserved in spirits of wine, jawbones with great teeth which grinned savagely at the unfortunate candidate, and numerous other zoological relics.