In the supplementary volumes, which appeared in 1776--ten years after the completion of the original undertaking--two new labourers came into the vineyard, whose names add fresh lustre and give still more serious value to the work. One of these was the prince of the physiologists of the eighteenth century, the great Haller, who contributed an elaborate history of those who had been his predecessors in unfolding the intricate mechanism of the human frame, and analysing its marvels of complex function. The other was the austere and generous Condorcet. Ever loyal to good causes, and resolute against despairing of the human commonwealth, he began in the pages of the Encyclopædia a career that was brilliant with good promise and high hopes, and ended in the grim hall of the Convention and a nobly tragic death amid the red storm of the Terror.
Among the lesser stars in the encyclopædic firmament are some whose names ought not to be wholly omitted. Forbonnais, one of the most instructive economic writers of the century, contributed articles to the early volumes, which were afterwards republished in his Elements of Commerce.[113] The light-hearted Marmontel wrote cheerful articles on Comedy, Eloges, Eclogues, Glory, and other matters of literature and taste. Quesnai, the eminent founder of the economic sect, dealt with two agricultural subjects, and reproduced both his theoretical paradoxes, and his admirable practical maxims, on the material prosperity of nations. Holbach, not yet author of the memorable System of Nature, compiled a vast number of the articles on chemistry and mineralogy, chiefly and avowedly from German sources, he being the only writer of the band with a mastery of a language which was at that moment hardly more essential to culture than Russian is now. The name of Duclos should not be passed over, in the list of the foremost men who helped to raise the encyclopædic monument. He was one of the shrewdest and most vigorous intelligences of the time, being in the front rank of men of the second order. His quality was coarse, but this was only the effect of a thoroughly penetrating and masculine understanding. His articles in the Encyclopædia (_Déclamation des Anciens_, _Etiquette_, etc.) are not very remarkable; but the reflections on conduct which he styled _Considérations sur les Moeurs de ce Siécle_ (1750), though rather hard in tone, abound in an acuteness, a breadth, a soundness of perception that entitle the book to the rare distinction, among the writings of moralists and social observers, of still being worth reading. Morellet wrote upon some of the subjects of theology, and his contributions are remarkable as being the chief examples in the record of the encyclopædic body of a distinctly and deliberately historic treatment of religion. "I let people see," he wrote many years after, "that in such a collection as the Encyclopædia we ought to treat the history and experience of the dogmas and discipline of the Christian, exactly like those of the religion of Brahma or Mahomet."[114] This sage and philosophic principle enabled him to write the article, Fils de Dieu (vol. vi.), without sliding into Arian, Nestorian, Socinian, or other heretical view on that fantastic theme. We need not linger over the names of other writers, who indeed are now little more than mere shadows of names, such as La Condamine, a scientific traveller of fame and merit in his day and generation; of Du Marsais, the poverty-stricken and unlucky scholar who wrote articles on grammar; of the President Des Brosses, who was unfortunate enough to be in the right in a quarrel about money with Voltaire, and who has since been better known to readers through the fury of the provoked patriarch, than through his own meritorious contributions to the early history of civilisation.