It is certain that at the time of his appointment to the super-intendancy his physical and mental strength had already become seriously impaired by the inroads of the insidious disease (Bright's) which ultimately, after several years of often intense suffering, ended in his death. That to some extent he was conscious of his enfeebled condition is evidenced by his remark when receiving the notice of his appointment, that ""it came too late"." Years before his life had been saddened by the loss of three young children; it was now darkened by the death of the last remaining son, Frederic, who, though always delicate, had lived to manhood and appeared to be entering upon a successful career as civil engineer. This blow, coming at a time when even in his letters he complained of increasing inability to do the accustomed amount of work, gave a grave downward impulse to his already failing strength. That he did not at that time find any one to lean upon as Bache had leaned upon him under similar circumstances was a misfortune which allowed matters to progress until a political change found in his case a welcome opportunity for the exhibition of the reformer's zeal. In respect to his physical and consequent mental condition at the time when he appeared before the Presidential commission on the conduct of the Coast Survey, it may suffice to say that the physician who examined him immediately after his resignation declared that had he been aware of the facts he "would, unsolicited and from a sense of justice, have gone before that body and testified that Hilgard could not be held responsible for his acts." This statement, amply corroborated by the severe illness immediately following, should dispose of the unjust censure visited upon him at the time, whether by those ignorant or by others forgetful of the devotion, singleness of purpose, and high ability which had uniformly marked his previous career. While there could be no question of the necessity for a change, the difficulty long experienced by the administration in finding a successor among his peers in science stands in evidence of the feeling excited in them by the harshness of the treatment bestowed upon him.