Towards his pupils he conducted himself with the most praiseworthy liberality. To those who were poor he remitted the fees due to him as professor, and even from the rich he on many occasions refused to receive any recompense. Dr Gieseke, when about to leave him in the autumn of 1771, pressed upon him a Swedish bank-note, as a remuneration for the trouble which he had taken in affording him instruction; but he was unwilling to accept it, and it was not till after the repeated entreaties of his pupil that he acceded to his request:--"Tell me candidly," said he, "if you are rich, and can afford it;--can you well spare this money on your return to Germany? If you can, give the note to my wife; but should you be poor, so help me God, I would not take a farthing from you!"--"To the praise of Linnaeus," says Mr Ehrhart, "I must farther own, notwithstanding his parsimony, that he neither would nor did accept a single penny as a fee for the lectures which he gave me. You are a Swiss," he once said to me, "and the only Swiss that visits me. I shall take no money of you, but feel a pleasure in telling you all that I know gratis." His excitable temper not unfrequently betrayed him into expressions which indicated a great want of self-control; but if he was easily roused to anger, he was as speedily appeased. He was exceedingly pleasant in conversation, humorous, and fond of telling entertaining stories. Constant in his attachments, he was ever disposed to look with indulgence on the faults of his friends; and he was fortunate in the affection which his pupils manifested towards him. But it is said that he was equally tenacious of dislike towards his enemies, or those of whom he had formed an unfavourable opinion. His opponents he treated with forbearance or contempt, and on no occasion engaged in controversy. In a letter to Haller he says,--"Our great example, Boerhaave, answered nobody whatever: I recollect his saying to me one day, 'You should never reply to any controversial writers; promise me that you will not.' I promised him accordingly, and have benefited very much by it." If he cherished animosity towards his adversaries, it certainly did not prevent him from expressing his esteem for their merits; and as dissimulation had no place in his character, he did not follow the example of those who by private misrepresentations undo the benefits conferred by public encomiums. "I am certain," says Murray, "that had his most unjust and most violent opponents heard him, they could not have refused him their esteem and affection."