As an indication of the exceptional merit of Agnesi's work, even long after its publication in 1748, it suffices to state that the second volume of the Instituzioni Analitiche was translated into French in 1775 by Antelmy and annotated by the Abbé Bossuet, a member of the French Academy and a collaborator of D'Alembert on the mathematical part of the famous Encyclopédie.
A still greater proof of the estimation in which Agnesi's work was held by men of science is the fact that it was translated in its entirety into English by the Rev. John Colton, Lucasian Professor of Mathematics in the University of Cambridge, and published in 1801, fifty-two years after it had appeared in Italian. His impression of the methods followed by the Milanese savante was so favorable that, in the words of a contemporary writer, it "gave rise to his very spirited resolution of learning a new language at an advanced period of life, that he might make himself perfect master of them."[118]
Gratifying, however, as were the tributes of admiration and appreciation which came to Agnesi from all quarters, from learned societies, from eminent mathematicians, from sovereigns—the Empress Maria Theresa sent her a splendid diamond ring and a precious crystal casket bejeweled with diamonds—that which touched her most deeply was, undoubtedly, the recognition which she received from the great Mæcenas of his age, Pope Benedict XIV. As Cardinal Lambertini and Archbishop of Bologna, he had taken a conspicuous part in the honors showered on Laura Bassi when she received her doctorate, and was specially delighted when she was made professor of physics in his favored university. Being himself familiar with the higher mathematics, he recognized at once the exceptional merit of Maria Gaetana's work and showed his appreciation of it not only by letters and presents, but also by having her, motu proprio, appointed by the Bolognese senate as professor of higher mathematics in the University of Bologna.
In advising her of this appointment, he writes her that he had in view the honor of the University in which he had always taken a special interest, and that the appointment carried with it no obligation of thanks on her part but rather on his—che porta seco ch'ella non deve ringraziar Noi, ma che Noi dobbiamo ringraziar lei. The interest that this wise and broad-minded pontiff exhibited in the advancement of learned women and the rewards he was ever ready to accord to their achievements in science and literature—especially in the cases of Laura Bassi and Maria Gaetana Agnesi—is in keeping with the policy pursued by his predecessors, and accounts in great measure for that large number of learned women in Italy who, since the opening of the first universities, have been the glory of their sex and country.
But ardent as was the desire of the Supreme Pontiff to have Agnesi occupy the chair of mathematics, and numerous as were the appeals of her friends and the members of the university faculty to have her accept the appointment that carried with it such signal honor, she could never be induced to leave her beloved Milan. For, after completing her masterpiece, she resolved to retire from the world and devote the rest of her life to the care of the poor, the sick and the helpless in her native city. She did not, however, as is so frequently asserted, enter the convent and become a nun.[119] During many years after her retirement from the world, she lived in her own home, a part of which she had converted into a hospital. During the last fifteen years of her life she had charge of the Pio Albergo Trivulzio—a large institution founded by Prince Trivulzio for the aged poor who were without home or assistance.
She had devoted ten years of the flower of her life to the writing of her Instituzioni Analitiche—prepared primarily for the benefit of one of her brothers who had a taste for mathematics—and, after it was finished, she entered upon that long career of heroic charity which was terminated only at her death at the advanced age of eighty-one.
One loves to speculate regarding Maria Gaetana's possible achievements if she had continued during the rest of her life that science in which, during a few short years, she had won such distinction. She had made her own the discoveries of Newton, Leibnitz, Roberval, Fermat, Descartes, Riccati, Euler, the brothers Bernouilli, and had mastered the entire science of mathematics then known. Her pinions were trimmed for essaying loftier flights than any hitherto attempted, and her intellect was prepared, as one of her scientific friends expressed it, "for fixing the limits of the infinite." But while the world of science was still sounding her praises and predicting for her still greater triumphs in the field of analysis, it learned with surprise and sorrow that she had bid adieu to those studies in which she had achieved such extraordinary success, and had consecrated her life to the service of the poor and the afflicted. She disappeared completely from those literary and scientific reunions where she had so long been the most conspicuous figure, and was thenceforth known only as the ministering angel of the suffering and the abandoned. For half a century hers was a life of the most heroic charity and self-abnegation. Very readily, therefore, we can understand why a recent representative of the scientific world should desire to see her name placed on the calendar of saints.[120]
Had Agnesi devoted her entire life to science instead of abandoning it just when she was prepared to do her best work, she might to-day be ranked among such supreme mathematicians as Lagrange, Monge, Laplace and the Bernouillis, all of whom were her contemporaries. Even as it was, she has been placed beside Cardan, Leibnitz and Euler for her remarkable powers of analysis of infinitesimals, while the best proof of the literary value of her Instituzioni Analitiche is the fact that it has been selected by the famous society Della Crusca as a testo di lingua—a work considered as a classic of its kind and used in the preparation of the great authoritative dictionary of the Italian language.
But by consecrating herself to charity she probably accomplished far more for humanity and for the well-being of her sex than if she had elected to continue her work in the higher mathematics. There had been many learned women in Italy before her time and many since; many who were distinguished as Hellenists, as Latinists, as polyglots, as mathematicians—women like the Roccati, the Borghini, the Brassi, the Ardinghelli, the Barbapiccola, the Caminer Turra, the Tambroni; but Maria Gaetana Agnesi surpasses them all, not only in knowledge, but as a potent influence for the diffusion of culture and the spirit of brotherhood, for the expansion of benevolence and charity, and, above all, for the elevation of woman. She was also, as her latest and best biographer beautifully expresses it, "an inspired condottiera who, in the field of civility, anticipated the conquests of these latter days." She was, indeed, as her epitaph informs us, pietate, doctrina, beneficentia insignis, and as such she will live in the memory of our race as long as men shall admire genius and love virtue.
In the year following the publication of Agnesi's Instituzioni Analitiche was recorded the premature and tragic death of the distinguished French mathematician, the Marquise Émilie du Châtelet. She has been described as a "thinker and scientist, précieuse and pedant, but not the less a coquette—in short, a woman of contradictions."[121] To most readers she is better known by reason of her liaison with Voltaire, of whom she is regarded as a mere satellite, than for her work in science. But she was far more than a satellite that shone by the light received from the sage of Ferney. For there can be no doubt that she was a highly gifted woman who, besides having a thorough knowledge of several languages, including Latin, possessed a special talent for mathematics. It was said of her that "she read Virgil, Pope and algebra as others read novels," and that she was able "to multiply nine figures by nine others in her head." No less an authority than the illustrious Ampère declared her to be "a genius in geometry."