Author(s):

Frank J. Swetz (The Pennsylvania State University)

Silvestre Lacroix first wrote his *Elements of Algebra* *for the Use of the Central School of* *Four Nations*. This institution was established in Paris in 1795 as a result of the French Revolution. Five such schools were planned to better serve the common people; however, only three were actually founded. In 1802, the Central School was discontinued. The fourteenth edition of the *Algebra*, as shown here, was published in 1825.

This excerpt from the Contents (pages *vj* and *vij*) shows some of the topics presented in this “revised and corrected” edition.

On page 13 of the *Algebra*, Lacroix demonstrated the conversion of a problem into algebraic form.

Page 147 contains a discussion of rational and irrational numbers: \(\sqrt{2}\) is noted as being “incommensurable or irrational.”

*This material is obtained through the courtesy of the University of California Libraries. A complete digital copy can be read on the Internet Archive.*

Index to Mathematical Treasures

Frank J. Swetz (The Pennsylvania State University), "Mathematical Treasure: Lacroix's Elements of Algebra," *Convergence* (February 2017)