“. . . I am, I assure you, deeply concerned to hear that you think so poorly of Dr. Tennant’s health; and perfectly disturbed to think that he has had any trouble about my thermometers.* The truth is I wished to avail myself of his intuitive skill in framing an instrument free of all exception for taking heat in contagious diseases where approach is hazardous. But since he left us . . . I have so far succeeded in constructing a sensible [? sensitive] instrument with Six’s iron index as to answer my purpose. . . . I have done very little but read Voltaire since I saw you. He is an exquisite fellow. One thing in him is peculiarly striking—his clear knowledge of the limits of the human understanding. He pursues his game as far as the scent carries him, but no further. Where this fails, he turns off with a jest, that marks distinctly where a wise man ought to stop. . . . You know, my dear fellow, I owe the delight of reading him to you.”
