LEWIS DU, natural son to Jean Louis de Montcalm Seigneur de Candiac, and a widow of rank of Rouergue, was born at Nîmes in 1676. His first attention was bestowed on jurisprudence; but afterwards he was altogether occupied with mathematics, philosophy, and the study of the languages. Father Malebranche cultivated his acquaintance and esteemed his virtues. His first appearance was severe, his general temper tranquil; yet he had a lively and fertile imagination. His mind was active, full of resources, and methodical. We are indebted to his industry for the Typographical Bureau. This invention is the more ingenious, as it presents the tedious parts of education, namely, reading, writing, and the elements of languages, to the youthful mind as a delightful entertainment; and many people in France, both in the capital and in the provinces, have adopted it with success. After he had conceived the idea of this invention, he made the first trial of it on the young Candiac, who was remarkable for his understanding in his earliest years. Du Mas conducted his pupil to Paris and the principal cities in France, where he was universally admired. This prodigy was carried off in the year 1726 before he was seven years of age, and his loss had nearly deprived Du Mas of his reason. A dangerous illness was the consequence of his vexation; and he would have died of want, if a gentleman had not taken him from his garret and entertained him in his own house. Du Mas afterwards retired with Madame de Vaujour within two leagues of Paris, and died in the year 1774, aged 68. He was a philosopher both in genius and character. His works are, 1. L'Art de transposer toutes sortes de Musiques sans être obligé de connoître, ni le temps, ni le mode, published at Paris in 4to. 1711. This work is extremely curious, but of no advantage to the study of music. 2. A volume in quarto, printed at Paris 1733, in four parts, entitled, Bibliothèque des enfants. In this treatise he has placed in a clear point of view, the system and economy of his Typographical Bureau. This invention, like everything new, was censured by some and admired by others. The author himself defended it with much success in the journals and in several occasional pamphlets. This collection, however, is become exceedingly scarce. The Typographical Bureau was brought to perfection by M. Reybert a citizen of Avignon, who enriched it with many articles containing useful and agreeable information in geography, history, fable, &c. &c. 3. Memoires de l'Ecole sous le regne de Marie Stuart, by Crawford, and translated from the English. This translation was found in manuscript in the library of the marquis d'Aubais, with whom Du Mas had lived in the most intimate habits of friendship.

MAS Planta, a plant which upon the same root produces male flowers only. See MASCULUS FLOS, Botany Index.