What endless marvels the world offered and how much there was to know about them! One lifetime was not nearly long enough. “The rapid progress true science now makes occasions my regretting sometimes that I was born so soon,” he wrote Joseph Priestley after their countries were at peace once more. “It is impossible to imagine the height to which may be carried, in a thousand years, the power of man over matter.... O that moral science were in as fair a way of improvement that men would cease to be wolves to one another, and that human beings would at length learn what they now improperly call humanity.” He could not guess that his fervent cry would still be echoed, in one form or another, more than a hundred and seventy-five years after his death.
In 1784, the King of France chose him to serve on a commission of five to investigate the work of Dr. Franz Anton Mesmer, who claimed to effect cures through “animal magnetism,”—a universal fluid which flowed to his patients from the healer, or from some object “magnetized” by the healer, such as a tree. All fashionable Paris was flocking to Mesmer’s seances; his following was enormous throughout France.
With Franklin on this commission served Joseph-Ignace Guillotin (whose name would survive in the French Revolution’s chief instrument of execution) and the scientist Lavoisier (whom the guillotine would claim as a victim). After many months of study, the commission concluded that “animal magnetism” did not exist, and that Mesmer’s cures were the result of “imagination.” The importance of imagination in physical illness was as yet unrecognized. Privately Franklin commented that Mesmer’s treatments certainly did some good—at least they kept some from taking injurious drugs.
On the whole the findings of the commission brought both Mesmer and mesmerism into disrepute. Indirectly the shadow of its disapproval fell on a phenomenon first discovered by a Mesmer disciple, the Marquis de Puysegur—that some persons, in a state of trance and apparently asleep, are able to obey simple commands. Hypnotism, for many years after de Puysegur’s observations, was relegated to quacks rather than physicians and scientists.
In August of 1784 Thomas Jefferson arrived from America to help negotiate treaties with European and North African powers. Franklin introduced him to his French scientific friends and found in his company the same harmony as when they were both members of the Second Continental Congress. His last winter in France, Polly Hewson and her children also joined him at Passy. Mrs. Stevenson, Polly’s mother, had died in England during the war. Franklin welcomed these members of his “English family” with joy and affection.
He still had his two grandsons with him. There had been some objections from Congress to his making Temple his secretary, on the grounds that he was the son of a traitor. Franklin had been highly indignant: “Methinks it is rather some merit that I have rescued a valuable young man from the danger of being a Tory, and fixed him in honest republican Whig principles.”
Yet there was some justification in the fears of Congress. At twenty-six, Temple was charming, handsome and spoiled. He spent his evenings at music halls and, wearing red heels, an embroidered coat, and with an Angora cat on a leash, paraded the boulevards with aristocratic young friends. Mockingly the Parisians dubbed him “Franklinet.” While Franklin was trying to kill a clause in the peace treaty conceding special privileges to Tories, Temple, without his knowledge, wrote to Lord Shelburne pleading a government post for his Tory father.
Different as could be was Benjamin Bache, now sixteen, a husky wholesome youngster much like Franklin at his age. He wanted no more than to be a printer as his grandfather had been. Franklin taught him how to cast type, and in April 1785 persuaded the best printer in France to make him an apprentice. The arrangement was of short duration.
In May, Franklin at last received permission from Congress to come home. Jefferson was appointed ambassador to France in his stead. “I am not replacing Franklin,” Jefferson said loyally. “No one could do that. I am only his successor.”
He left Passy on July 12, 1785, traveling to Havre in a royal litter drawn by mules, which the King had provided for his comfort. His personal goods—128 boxes in all—went by barge down the Seine. He took with him Louis XVI’s personal gift—the King’s miniature, set with 408 diamonds. The whole population of Passy watched him leave, silent except for occasional outbursts of sobs.