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.