A few years afterwards Morse and his associates became involved in a series of bitterly contested litigations with parties interested in breaking down the original patent rights, and Henry was called as a witness for the opponents of Morse.
He gave his testimony with great reluctance, but it was tinged with the bitterness caused by the failure of Vail to do him justice and his apparent conviction that Morse was disingenuous. He denied to the latter any scientific discoveries, and gave the impression (at least, to others) that Henry, and not Morse, was the real inventor of the telegraph. His testimony was used by the enemies of Morse, both at home and abroad, to invalidate the claims of the latter, and, stung by these aspersions on his character and attainments, and urged thereto by injudicious friends, Morse published a lengthy pamphlet entitled: "A Defense against the Injurious Deductions drawn from the Deposition of Professor Joseph Henry." In this pamphlet he not only attempted to prove that he owed nothing to the discoveries of Henry, but he called in question the truthfulness of that distinguished man.
The breach between these two honorable, highly sensitive men was now complete, and it was never healed.
The consensus of scientific opinion gives to Henry's discoveries great value in the invention of the telegraph. While they did not constitute a true telegraph in themselves; while they needed the inventions and discoveries, and, I might add, the sublime faith and indomitable perseverance of Morse to make the telegraph a commercial success; they were, in my opinion, essential to it, and Morse, I think, erred in denying this. But, from a thorough study of his character, we must give him the credit of being sincere in his denial. Henry, too, erred in ignoring the advances of Morse and Vail and in his proud sensitiveness. Professor Leonard D. Gale, the friend of both men, makes the following comment in a letter to Morse of February 9, 1852: "I fear Henry and I shall never again be on good terms. He is as cold as a polar berg, and, I am informed, very sensitive. It has been said by some busybody that his testimony was incompatible with mine, and so a sort of feeling is manifested as if it were so. I have said nothing about it yet." It would have been more dignified on the part of Morse to have disregarded the imputations contained in Henry's testimony, or to have replied much more briefly and dispassionately. On the other hand, the provocation was great and he was egged on by others, partly from motives of self-interest and partly from a sincere desire on the part of his friends that he should justify himself.
In a long letter to Vail, of January 15, 1851, in which he details the whole unfortunate affair, he says: "If there was a man in the world, not related to me, for whom I had conceived not merely admiration but affection, it was for Professor Joseph Henry. I think you will remember, and can bear me witness, that I often expressed the wish that I was able to put several thousand dollars at his service for scientific investigation…. The whole case has saddened me more than I can express. I have to fight hard against misanthropy, friend Vail, and I have found the best antidote to be, when the fit is coming on me, to seek out a case of suffering and to relieve it, that the act in the one case may neutralize the feeling in the other, and thus restore the balance in the heart."
In taking leave for the present of this unfortunate controversy I shall quote from the "Defense," to show that Morse sincerely believed it his duty to act as he did, but that he acted with reluctance:—
"That I have been slow to complain of the injurious character of his testimony; that I have so long allowed, almost entirely uncontradicted, its distortions to have all their legal weight against me in four separate trials, without public exposure and for a space of four years of time, will at least show, I humbly contend, my reluctance to appear opposed to him, even when self-defence is combined with the defence of the interests of a large body of assignees…. Painful, therefore, as is the task imposed upon me, I cannot shrink from it, but shall endeavor so to perform it as rather to parry the blows that have been aimed at me than to inflict any in return. If what I say shall wound, it shall be from the severity of the simple truth itself rather than from the manner of setting it forth."
In the year 1846 there still remained one panel in the rotunda of the Capitol at Washington to be filled by an historical painting. It had been assigned to Inman, but, that artist having recently died, Morse's friends, artists and others, sent a petition to Congress urging the appointment of Morse in his place. Referring to this in a letter to his brother Sidney, dated March 28, he says:—
"In regard to the rotunda picture I learn that my friends are quite zealous, and it is not improbable that it may be given me to execute. If so, what should you say to seeing me in Paris?
"However, this is but castle-building. I am quite indifferent as to the result except that, in case it is given me, I shall be restored to my position as an artist by the same power that prostrated me, and then shall I not more than ever have cause to exclaim: 'Surely Thou hast led me in away which I knew not'? I have already, in looking back, seen enough of the dealings of Providence with me to excite my wonder and gratitude. How singularly has my way been hedged up in my profession at the very moment when, to human appearance, everything seemed prosperously tending to the accomplishment of my desire in painting a national picture. The language of Providence in all his dealings with me has been almost like that to Abraham: 'Take now thy son, thine only son Isaac whom thou lovest, and offer him for a burnt offering,' etc.