Arthur Young, well known in his day as a traveler and author, who in 1787 made the acquaintance of Madame Lavoisier, describes her as a woman full of animation, good sense and knowledge. In referring to a breakfast she had given him, he declares that "unquestionably the best part of the repast was her conversation on Kirwan's _Essay on Phlogiston_, which she was then translating, and on other subjects which a woman of sense, working in the laboratory of her husband, knows so well how to make interesting." She was an ardent co-worker with her husband in his laboratory and materially aided him in his labors. Under his direction she wrote the results of the experiments that were made, as is evidenced by the records of his work. As a pupil of the illustrious painter, David, she was naturally skillful in drawing. Besides this, she was a good engraver, and it is to her that are due the illustrations in Lavoisier's great _Traite de Chimie_, which contributed so much toward revolutionizing the science of chemistry. It was, indeed, the first work that deserved to be regarded as a textbook of modern chemistry. Among her drawings are two of special interest. They represent her as seated at a table in the laboratory, taking notes, while her husband and his assistant, Seguin, are making an experiment on the phenomena of respiration.[158] All Mme. Lavoisier's writings testify to her great admiration of the genius of her husband. Intimately associated with him in his work, she combatted for the triumph of his ideas and sought to make converts to them. One of her most notable converts was the Swiss chemist, de Saussure. "You have, Madame," he writes her, "triumphed over my doubts, at least in the matter of phlogiston, which is the principal object of the interesting work of which you have done me the honor of sending me a copy." After Lavoisier's tragic death on the guillotine, it was his devoted wife who edited his _Memoirs on Chemistry_, of which Lavoisier had himself projected the publication. The two volumes constituting this work were not for sale, but were gratuitously distributed by the bereaved widow among the most eminent scientific men of the epoch. Cuvier, in acknowledging the receipt of these precious memoirs, declares: "All the friends of science are under obligations to you for your sorrowful determination to publish this collection of papers and to publish them as they were written--a melancholy monument of your loss and theirs--a loss which humanity will feel for centuries."