(b. Milan, Italy, ca, 1751; d. Vienna, Austria, not later than 1816)
We have no information about Landriani until 1775, when the Ricerche fisiche intorno alla salubrité dell’ria appeared. In 1776 he was appointed teacher of physics in the schools of higher education then being established in Milan. By appointment of the government, in 1787–1788 he made a long tour of the leading countries of Europe in order to study their scientific and technological development. In 1790 he was government adviser, and in this capacity he ordered the establishment of the Veterinary School of Milan. Toward the end of 1791 he was sent on a diplomatic mission to Dresden, where he continued to study physics, spreading knowledge of Galvani’s recent electrophysiological discoveries. In 1794 he moved to Vienna, where he spent the remaining years of his life.
Landriani’s name is repeatedly linked to Volta’s inventions (from the electrophorus to the Pile) and especially to the eudiometer. The term (derived from the Greek eudia [“fair weather”]) was first used by Landriani in the Richerche to indicate the instrument he had devised to measure the purity of the air. The method had been introduced in 1772 by Joseph Priestley, who had proposed measuring the “different disposition of airs for breathing” by means of the NO +O2 reaction: “nitrous air” (nitrogen bioxide) plus the gas of common air, which Priestley himself obtained in 1774 and called “dephlogisticated air” (later named oxygen by Lavoisier). By means of this reaction reddish vapors (higher oxides of nitrogen) are formed; being strongly water soluble, they are removed by water, in the presence of which the reaction is carefully performed. The reaction thus indicates the consumption of oxygen, or part of common air. The greater the reduction in volume that the latter undergoes, the richer in oxygen it is and hence the healthier.
Volta very acutely defined the hygienic value of the method and radically transformed the instrument, assigning it new tasks. In 1777 the eudiometer entered the history of science as a valued instrument for analyzing gases.
I. Original Works. Landriani’s writings are Ricerche fische intorno alla salubritá dell’aria (Milan, 1775); Physikalische Untersuchugen über die Gesundheit der Luft (Basel, 1778; Bern, 1792); “Lettera al Signor D. alessandro Volta,” in Scelta di puscoli interssanti. 19 (1776), 73–86, with a plate; Opuscoli fisco-chimici (Milan, 1781); Dell’ utilitá dei conduttori elettrici (Vienna, 1786); “Von einigen Entdeckungen in der thierischen Elektricitàt,” in Sammlung physikalischer Aufsàtze, besonders die Bömische Naturgeschichte betreffend, von einer Gesellschaft Böhmischer Naturforscher, 3 (1793), 384–388, with 2 plates; and Relazione sopra Basilea, Aarau e Bienne, which follows the reprint of Pietro Moscati and M. Landriani, Dei vantaggi della educazione filsofica nello studio della chimica, Luigi Belloni, ed. (Milan, 1961).
II. Secondary Literature. On Landriani and his work, see Luigi Belloni, “L’eudiometro del Landriani (contributioalla stroia medica dell’edutiometria),” in Actes du symposium international sur les sciences naturelles, la chimie et la pharmacie du 1630 au 1850, Florence-Cinci, 8–10 octobre 1960 (Florence, 1962), 130–151; “La salbritá dell’aria: l’eudiometro del Landriani,” in Fondazione Treccani degli Alfieri, Storia di Milano, XVI (Milan, 1962), 946–947; and “La Scuola Veterinaria di Milano, Discorso celebrativo del 175° anniversario di fondazione della Scuola oggi Facoltà di Medicina Veterinaria letto il 14 ottobre 1966,” in Studium veterinar mediolanese, 1 (1969), 1–32.