A melancholy group they were, sallow-faced, long-visaged and dolorous, partly from the effects of a long course of study and partly from their present trepidation. It was painful to observe their attempts to appear confident and unconcerned as they glanced round the heavens, as if to observe the state of the weather, or examined with well-feigned archaeological fervour the inscriptions upon the old University walls. Most painful of all was it, when some one, plucking up courage, would venture upon a tiny joke, at which the whole company would gibber in an ostentatious way, as though to show that even in this dire pass the appreciation of humour still remained with them. At times, when any of their number alluded to the examination or detailed the questions which had been propounded to Brown or Baker the day before, the mask of unconcern would be dropped, and the whole assembly would glare eagerly and silently at the speaker. Generally on such occasions matters are made infinitely worse by some Job's comforter, who creeps about suggesting abstruse questions, and hinting that they represent some examiner's particular hobby. Such a one came to Dimsdale's elbow, and quenched the last ray of hope which lingered in the young man's bosom. "What do you know about cacodyl?" was his impressive question. "Cacodyl?" Tom cried aghast. "It's some sort of antediluvian reptile, isn't it?" The questioner broke into a sickly smile. "No," he said. "It's an organic explosive chemical compound. 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. The second table was heaped over with a blaze of gorgeous orchids and tropical plants, which looked strangely out of place in the great bleak room. A row of microscopes bristled along the edge. The third was the most appalling of all, for it was bare with the exception of several sheets of paper and a pencil. Chemistry was the most dangerous of the many traps set to ensnare the unwary student.