OZANAM (James)

, an eminent French mathematician, was descended from a family of Jewish extraction, but which had long been converts to the Romi<*>h faith; and some of whom had held considerable places in the parliaments of Provence. He was born at Boligneux in Bressia, in the year 1640; and being a younger| son, though his father had a good estate, it was thought proper to breed him to the church, that he might enjoy some small benefices which belonged to the family, to serve as a provision for him. Accordingly he studied divinity four years; but then, on the death of his father, he devoted himself entirely to the mathematics, to which he had always been strongly attached. Some mathematical books, which fell into his hands, first excited his curiosity; and by his extraordinary genius, without the aid of a master, he made so great a progress, that at the age of 15 he wrote a treatise of that kind.

For a maintenance, he first went to Lyons to teach the mathematics; which answered very well there; and after some time his generous disposition procured him still better success elsewhere. Among his scholars were two foreigners, who expressing their uneasiness to him, at being disappointed of some bills of exchange for a journey to Paris; he asked them how much would do, and being told 50 pistoles, he lent them the money immediately, even without their note for it. Upon their arrival at Paris, mentioning this generous action to M. Daguesseau, father of the chancellor, this magistrate was touched with it; and engaged them to invite Ozanam to Paris, with a promise of his favour. The opportunity was eagerly embraced; and the business of teaching the mathematics here soon brought him in a considerable income: but he wanted prudence for some time to make the best use of it. He was young, handsome, and sprightly; and much addicted both to gaming and gallantry, which continually drained his purse. Among others, he had a love intrigue with a woman, who lodged in the same house with him, and gave herself out for a person of condition. However, this expence in time led him to think of matrimony, and he soon after married a young woman without a fortune. She made amends for this defect however by her modesty, virtue, and sweet temper; so that though the state of his purse was not amended, yet he had more home-felt enjoyment than before, being indeed completely happy in her, as long as she lived. He had twelve children by her, who mostly all died young; and he was lastly rendered quite unhappy by the death of his wife also, which happened in 1701. Neither did this misfortune come single: for the war breaking out about the same time, on account of the Spanish succession, it swept away all his scholars, who, being foreigners, were obliged to leave Paris. Thus he sunk into a very melancholy state; under which however he received some relief, and amusement, from the honour of being admitted this same year an eleve of the Royal Academy of Sciences.

He seems to have had a pre-sentiment of his death, from some lurking disorder within, of which no outward symptoms appeared. In that persuasion he refused to engage with some foreign noblemen, who offered to become his scholars; alleging that he should not live long enough to carry them through their intended course. Accordingly he was seized soon after with an apoplexy, which terminated his existence in less than two hours, on the 3d of April 1717, at 77 years of age.

Ozanam was of a mild and calm disposition, a chearful and pleasant temper, endeared by a generosity almost unparalleled. His manners were irreproachable after marriage; and he was sincerely pious, and zealously devout, though studiously avoiding to meddle in theological questions. He used to say, that it was the business of the Sorbonne to discuss, of the pope to decide, and of a mathematician to go straight to heaven in a perpendicular line. He wrote a great number of useful books; a list of which is as follows:

1. A treatise of Practical Geometry; 12mo, 1684.

2. Tables of Sines, Tangents and Secants; with a treatise of Trigonometry; 8vo, 1685.

3. A treatise of Lines of the First Order; of the Construction of Equations; and of Geometric Lines, &c; 4to, 1687.

4. The Use of the Compasses of Proportion, &c; with a treatise on the Division of Lands; 8vo, 1688.

5. An Universal Instrument for readily resolving Geometrical Problems without calculation; 12mo, 1688.

6. A Mathematical Dictionary; 4to, 1690.

7. A General Method for drawing Dials, &c; 12mo, 1693.

8. A Course of Mathematics, in 5 volumes, 8vo, 1693.

9. A treatise on Fortisication, Ancient and Modern; 4to, 1693.

10. Mathematical and Philosophical Recreations; 2 vols 8vo, 1694; and again with additions in 4 vols, 1724.

11. New Treatise on Trigonometry; 12mo, 1699.

12. Surveying, and measuring all sorts of Artificers Works; 12mo, 1699.

13. New Elements of Algebra; 2 vols 8vo, 1702.

14. Theory and Practice of Perspective; 8vo, 1711.

15. Treatise of Cosmography and Geography; 8vo, 1711.

16. Euclid's Elements, by De Chales, corrected and enlarged; 12mo, 1709.

17. Boulanger's Practical Geometry enlarged, &c; 12mo, 1691.

18. Boulanger's treatise on the Sphere corrected and enlarged; 12mo.

Ozanam has also the following pieces in the Journal des Sçavans: viz, (1), Demonstration of this theorem, that neither the Sum nor the Difference of two Fourth Powers, can be a Fourth Power; Journal of May 1680. —(2), Answer to a Problem proposed by M. Comiers; Journal of Nov. 17, 1681.—(3), Demonstration of a Problem concerning False and Imaginary Roots; Journal of April 2 and 9, 1685.—(4), Method of finding in Numbers the Cubic and Sursolid Roots of a Binomial, when it has one; Journal of April 9, 1691.

Also in the Memoires de Trevoux, of December 1703, he has this piece, viz, Answer to certain articles of Objection to the first part of his Algebra.

And lastly, in the Memoirs of the Academy of Sciences, of 1707, he has Observations on a Problem of Spherical Trigonometry.|