for they could only guess vaguely at the cause of this sudden separation.
The Professor was as punctual as ever at his classes, and as zealous in directing the laboratory work of those who studied under him. His own private researches were pushed on with feverish energy. It was no uncommon thing for his servants, when they came down of a morning, to hear the shrill scratchings of his tireless pen, or to meet him on the staircase as he ascended, grey and silent, to his room. In vain his friends assured him that such a life must undermine his health. He lengthened his hours until day and night were one long, ceaseless task.
Gradually under this discipline a change came over his appearance. His features, always inclined to gauntness, became even sharper and more pronounced. There were deep lines about his temples and across his brow. His cheek was sunken and his complexion bloodless. His knees gave under him when he walked; and once when passing out of his lecture-room he fell and had to be assisted to his carriage.
This was just before the end of the session and soon after the holidays commenced the professors who still remained in Birchespool were
