For two seasons De Loutherbourg's Eidophusikon, exhibited at the Patagonian Theatre in Exeter Change, and afterwards at a house in Panton Square, was attended with singular success. Crowds flocked to the new entertainment; the artist world especially delighting in it. Sir Joshua Reynolds, who was a frequent visitor, loudly extolled Mr. De. Loutherbourg's ingenuity; recommending him to the patronage of the most eminent men of the time, and counselling all art-students to attend the exhibition as a school of the wonderful effects of nature. Gainsborough's ready sympathies were completely enlisted. For a time, after his manner, he could talk of nothing else, think of nothing else; and he passed evening after evening at the exhibition. He even constructed a miniature Eidophusikon of his own—moved thereto by De Loutherbourg's success and the beauty of a collection of stained glass, the property of one Mr. Jarvis—and painted various landscapes upon glass and transparent surfaces, to be lighted by candles at the back, and viewed through a magnifying lens upon the peep-show principle. But at last the fickle public wearied of the Eidophusikon, as it had been wearied of Mr. Dibdin's puppets. The providers of amusement had, in those days, to be ever stirring in the production of novelties. The sight-seeing public was but a limited and exhaustible body then, little recruited by visitors from the provinces or travellers from the Continent. Long runs of plays or other entertainments—the rule with us—were then almost unknown. The Eidophusikon ceased to attract. The amount received at the doors was at last insufficient to defray the expenses of lighting the building. It became necessary to close the exhibition and provide a new entertainment. Soon the room in Exeter Change was crowded with visitors. Wild beasts were on view, and all London was gaping at them.

Meanwhile De Loutherbourg prospered as an artist. His reputation grew; his pictures were in request; he was honoured with the steady patronage of King George III., and was personally an acknowledged favourite at court: a thoroughly successful man indeed. Then we come down to the year 1789, and find the artist of the Eidophusikon assuming a new character. He has become a physician—a seer—a fanatic—and, it must be said, a quack; a disciple of Mesmer, a friend of Cagliostro; practising animal magnetism, professing to cure all diseases, and indulging in vaticination and second sight.

Towards the close of the eighteenth century, credulity and imposition shook hands heartily and held a great festival. Throughout civilized Europe a sort of carnival of empiricism prevailed. Quack was king. A spurious leaven of charlatanism was traceable in politics, in science, in religion—pervaded all things indeed. The world was mad to cheat or to be cheated. The mountebank enjoyed his saturnalia. Never had he exhibited his exploits before an audience so numerous and so sympathetic—so eager to be swindled, so liberal in rewarding the swindler. Gravely does Miss Hannah More address Mr. Horace Walpole, concerning what she terms the 'demoniacal mummery'—'the operation of fraud upon folly' which then occupied the country. 'In vain do we boast of the enlightened eighteenth century, and conceitedly talk as if human reason had not a manacle left about her, but that philosophy had broken down all the strongholds of prejudice, ignorance, and superstition; and yet, at this very time, Mesmer has got a hundred thousand pounds by animal magnetism in Paris, and Mainaduc is getting as much in London. There is a fortune-teller in Westminster who is making little less. Lavater's physiognomy books sell at fifteen guineas a set. The diving [divining?] rod is still considered as oracular in many places. Devils are cast out by seven ministers; and, to complete the disgraceful catalogue, slavery is vindicated in print and defended in the House of Peers! Poor human nature, when wilt thou come to years of discretion?' Mr. Walpole writes back (he has always a proper tone for Miss More, reserving his levity and license for less staid correspondents):—'Alas! while Folly has a shilling left, there will be enthusiasts and quack doctors;' and he adds, airing his pet affectation—a hatred of royalty, a love for republicanism—'and there will be slaves while there are kings or sugar-planters.'

Joseph Balsamo—more generally known by his pseudonym of Count Alexander De Cagliostro, expelled from France, after nine months' durance in the Bastille, on account of his complicity in the diamond necklace fraud and scandal—had taken refuge in England, bringing with him a long list of quackeries and impostures; among them, his art of making old women young again; his system of 'Egyptian freemasonry,' as he termed it, by virtue of which the ghosts of the departed could be beheld by their surviving friends; and the secrets and discoveries of the great Dr. Mesmer in the so-called science of animal magnetism. Walpole at once proclaims the man a rascal, and proposes to have him locked up for his mummeries and impositions. Miss More laments that people will talk of nothing else. 'Cagliostro and the cardinal's necklace,' she writes, 'spoil all conversation, and destroyed a very good evening at Mr. Pepys's last night' A discussion of such subjects was by no means compatible with Miss More's notion of a good evening.

What could have induced simple-minded Mr. De Loutherbourg to put trust in this arch-juggler? Can it have been that from the painter's native Strasbourg had come to him unimpeachable accounts of Cagliostro's feats during his stay there, which had preceded his nefarious expedition to Paris? But the artist is ever excitable, receptive, impressible—the ready prey of the dealer in illusion and trickery. De Loutherbourg is soon at the feet of the quack Gamaliel; soon he is proclaiming himself an inspired physician, practising mesmerism. Cosway and his wife declared themselves clairvoyants. Other painters of the period were dreaming dreams and seeing visions. Nor was it only the artist world that took up with, and made much of, Count Cagliostro and his strange doings. Wiser people than Mr. De Loutherbourg were led astray by the mountebank, though they did not wander so far from the paths of reason and right, nor publish so glaringly the fact of their betrayal into error. Cagliostro was the rage of the hour. The disciples of Dr. Mesmer were without number. It was in ridicule of general rather than class credulity that Mrs. Inchbald wrote (or adapted) her comedy of Animal Magnetism, produced on the stage of Covent Garden in 1788.

A curious fanatical pamphlet, by one Mary Pratt, of Portland Street, Marylebone, was published in 1789. It was entitled, A List of Curses performed by Mr. and Mrs. de Loutherbourg, of Hammersmith Terrace, without Medicine: By a Lover of the Lamb of God, and was dedicated to the Archbishop of Canterbury in very high-flown terms. Mr. De Loutherbourg was described as 'a gentleman of superior abilities, well known in the scientific and polite assemblies for his brilliancy of talents as a philosopher and painter,' who, with his wife, had been made proper recipients of the 'divine manuductions,' and gifted with power 'to diffuse healing to the afflicted; whether deaf, dumb, lame, halt, or blind.' The Archbishop was therefore entreated to compose a form of prayer to be used in all churches and chapels, that nothing might prevent the inestimable power of the De Loutherbourgs from having its free course, and to order public thanksgiving to be offered up for the same. In her preface, Mrs. Pratt stated that her pamphlet had been published without the consent of Mr. De Loutherbourg, and that he had reprimanded her on account of it, and enjoined her positively to suppress it; but that on mature reflection she had considered it more advisable to offend an individual rather than permit thousands of her fellow-creatures to remain strangers to the precious gifts of the painter. 'I judged by my own private feelings,' she writes, 'that had I any relative either deaf, dumb, blind, or lame, how thankful I should be to find a cure (more especially gratis); therefore I suffered the pamphlet to be sold, in hopes that by circulating these most solemn truths, many poor afflicted people might come and be healed.'

The cures enumerated in Mrs. Pratt's list would be marvellous enough if the slightest credit could be attached to the lady's wild statements. De Loutherbourg's treatment of the patients who flocked to him was undoubtedly founded on the practice of Mesmer, though Horace Walpole appears to draw a distinction between the curative methods of the two doctors, when he writes to the Countess of Ossory in July 1789: 'Loutherbourg the painter is turned an inspired physician, and has three thousand patients. His sovereign panacea is barley water. I believe it is as efficacious as mesmerism. Baron Swedenborg's disciples multiply also. I am glad of it. The more religions and the more follies the better: they inveigle proselytes from one another.' In a subsequent letter he writes, in reference to a new religion advocated by Taylor the Platonist:—'He will have no success. Not because nonsense is not suited to making proselytes—witness the Methodists, Moravians, Baron Swedenborg, and Loutherbourg the painter—but it should not be learned nonsense, which only the literate think they understand after long study. Absurdity announced only to the ear and easily retained by the memory has other guess operation. Not that I have any objection to Mr. Taylor for making proselytes: the more religions the better. If we had but two in the island they would cut one another's throats for power. When there is plenty of beliefs the professors only gain customers here and there from rival shops, and make more controversies than converts.' This letter was also written to the Countess of Ossory. It was hardly in so free a vein on such a subject that the writer would have ventured to address Miss Hannah More; with whom Mr. Walpole was fond of corresponding about this period.

In Mrs. Pratt's List we read of a lad named Thomas Robinson, suffering from the king's evil, and dismissed from St. Bartholomew's Hospital as incurable, brought before Mr. De Loutherbourg, who 'administered to him yesterday in the public healing-room, amidst a large concourse, among whom were some of the first families of distinction in the kingdom,' and wholly cured the sufferer. The two daughters born deaf and dumb of Mrs. Hook, Stable Yard, St. James's, waited upon Mrs. De Loutherbourg, 'who looked upon them with an eye of benignity and healed them.' 'I heard them both speak,' avers Mrs. Pratt, by way of settling the matter. Among other cures we find 'a man with a withered arm which was useless, cured in a few minutes by Mr. De Loutherbourg in the public healing-room at Hammersmith;' 'Mr. Williams, of Cranbourne Street, ill of a fever, had kept his bed ten weeks, was cured instantly;' 'a gentleman, confined with gout in his stomach, kept his bed, was cured instantly;' 'a green-grocer in Weymouth Street, Marylebone, next door to the Weavers' Arms, cured of lameness in both legs—went with crutches—is perfectly well;' 'a Miss W——, a public vocal performer, cured,—but had not goodness of heart enough to own the cure publicly;' 'a child cured of blindness, at Mr. Marsden's, cheesemonger, in the borough.' Other cases are set forth; but the reader will probably consider that specimens enough have been culled from Mrs. Pratt's pamphlet.

That the proceedings of the De Loutherbourgs attracted extraordinary attention is very certain. Crowds surrounded the painter's house at Hammersmith, so that it was with difficulty he could go in or out. Particular days were set apart and advertised in the newspapers as 'healing days,' and a portion of the house was given up as a 'healing-room.' Patients were admitted to the presence of the artist-physician by tickets only, and to obtain possession of these, it is said that three thousand people were to be seen waiting at one time. Mrs. Pratt recounts 'with horror and detestation 'the wickedness of certain speculators in the crowd, who, having procured tickets gratis, unscrupulously sold them, at a profit ranging from two to five guineas, to buyers who were tired of waiting. De Loutherbourg complained bitterly that out of the thousands he professed to have cured, but few returned to thank him for the great benefits he had conferred upon them. He preferred to believe in the ingratitude of his patients rather than adopt the more obvious and reasonable course of questioning the perfect virtue of his curative powers, Mrs. Pratt, in concluding her pamphlet, entreats the magistracy or governors of the police to wait on Mr. De Loutherbourg and consult with him as to a proper mode of promoting his labours, and suggests that a 'Bethesda' should be forthwith built for the reception of the sick, and that officers should be appointed to preserve decorum, and to facilitate the efforts of Mr. and Mrs. De Loutherbourg, 'without so much crowding.' Finally she exhorts the world at large to contribute generously to the promotion of these beneficial objects.

But even at the date of Mrs. Pratt's pamphlet the tide was turning—had turned. The nine days' wonder was over. The mania was dying of exhaustion. Incidentally, the lady relates that 'having suffered all the indignities and contumely that man could suffer,' the inspired physician had for a time retired from practice into the country. 'I have heard,' she continues, 'people curse him and threaten his life, instead of returning him thanks.' In truth, as the public credulity waned, the doctor's cures failed. His labours were of no avail; his prophecies were falsified. His patients rose against him; the duped grew desperate; the mob became exceeding wroth. The house in Hammersmith Terrace was attacked; stones were thrown, and windows smashed. Not much further mischief was done, however. De Loutherbourg and his wife prudently withdrew from public observation—quitted the kingdom. They were next heard of in company with their friend Count Cagliostro in Switzerland; Madame Cagliostro having accompanied them in their journey from England. But Count Cagliostro's career of jugglery and fraud was nearly over. On the night of the 27th December 1789, he was arrested in Rome, and shut up in the Castle of St. Angelo, whence he never emerged alive.