Paolo Ruffini

Paolo Ruffini, physician and mathematician, was born in Valentano, Papal States (now Italy) on September 22, 1765, and died on May 10, 1822 in Modena (now Italy). At first he intended to enter Holy Orders and went far until he received the tonsure (ceremony that gave him the first degree of Order in the clergy). However, changing his mind, he began studying mathematics and medicine at the University of Modena, where he received a doctorate degree. At twenty-three, he was appointed professor of analysis, after replacing his teacher Cassiani for a year.

In 1791, the elementary math chair was entrusted to him. Meanwhile, he did not neglect the study and practice of medicine. At the time of the French invasion of Italy (1796), he was unexpectedly appointed a member of the Juniori in the legislative body of Milan. It was not without difficulty that he succeeded in returning to his conferences in Modena. For refusing to take the Republican oath without the conditional statement dictated by his conscience, he was dismissed from his position as a public lecturer; but with the return of the Austrians in 1799 he was reinstated to his former post and held there by the following governments.

Ruffini declined a call to the highest math chair at Pavia because he did not wish to leave his medical practice. The university student had been degraded to the degree of lyceumHe accepted (1806) the applied mathematics chair at the newly established military school. In 1814 Francesco IV reinstated the university and appointed Ruffini rector for life, and at the same time professor of practical medicine and applied mathematics. Through his conferences with patients at the time, he revived the clinical studies that had been abandoned for several years. During the 1817 typhus epidemic he sacrificed himself for his fellow citizens, and finally succumbed. Although recovered, he never regained all his strength. He was buried in the Church of Santa Maria di Pomposa, between the tombs of Sigonio and Muratori.

Ruffini's unique medical treaty is a "contagious southern typhus memory." As a mathematician his name is inseparably associated with the proof of the impossibility of algebraically solving the equation of degree 5, in which he wrote several treatises ("General theory of equation, in which it is impossible to prove the algebraic solution of the general equation of higher degree 4 ° ", 2 volumes., Bologna, 1798 ;;" Della soluzione delle equazioni alg. determinate particolari di grad sup. at 4 ° "in" Mem. Soc. Ital "., IX, 1802 which was awarded by the National Institute of Milan;" Della insolubilità etc. any method if adapted, algebraic this is the transcendent "in" Mem. Inst. Naz. Ital "., I, 1806).

He also proved the impossibility of squaring the circle ("Riflessioni intorno alla rectification ed alla square of the circus Lesser known, however, is the fact that Ruffini published the now familiar "Horner's method" of approximation to the roots of numerical equations fifteen years before the first paper. of Horner In 1802 the Italian Society of Forty offered a gold medal for the best method of determining the root of a numerical equation of any degree. In 1804 the medal was awarded to Ruffini, and the dissertation was published under the title " Blow on the determination of the radix in the numerical number of the grad ".

In a paper read before the Southwestern Section of the American Mathematical Soc (Nov. 26, 1910), Professor Florian Cajori showed that the computation required by Ruffini is identical to that in the "Horner method", and that this method is elaborated. by Ruffini with a clarity and effectiveness not surpassed in Horner's own exposition in 1819. Because of this fact, Professor Cajori insists, that the name of Ruffini should be associated with that of Horner in the designation of the method.

Ruffini wrote again on this subject in 1807 (Elementary Algebra, ch. Iv, v), and in 1813 (Memorie Soc. It., XVI, XVII). Ruffini was a jealous Catholic throughout his life. His convictions find expression in his apologetic works: "Dell 'immortalità dell' animates"(Modena, 1806), dedicated to Pius VII who sent him a gold medal;"Riflessioni criticizes blowing the philosophical sagacity around the probability of the Sig. Tell me about the place "(Modena, 1821), in which he proves that he is as familiar with metaphysics as with questions of religion.

Information was taken from the Catholic Encyclopedia.