a charge applied to the spinal cord of a frog could generate muscular spasms throughout its body. Charges could make frog legs jump even if the legs were no longer attached to a frog. While cutting a frog leg, Galvani's steel scalpel touched a brass hook that was holding the leg in place. The leg twitched. Further experiments confirmed this effect, and Galvani was convinced that he was seeing the effects of what he called animal electricity, the life force within the muscles of the frog. At the University of Pavia, Galvani's colleague Alessandro Volta was able to reproduce the results, but was sceptical of Galvani's explanation. Lazzaro Spallanzani is one of the most influential figures in experimental physiology and the natural sciences. His investigations have exerted a lasting influence on the medical sciences. He made important contributions to the experimental study of bodily functions and animal reproduction. Francesco Redi discovered that microorganisms can cause disease. 19th century Until the late 19th or early 20th century, scientists were still referred to as "natural philosophers" or "men of science". English philosopher and historian of science William Whewell coined the term scientist in 1833, and it first appeared in print in Whewell's anonymous 1834 review of Mary Somerville's On the Connexion of the Physical Sciences published in the Quarterly Review. Whewell wrote of "an increasing proclivity of separation and dismemberment" in the sciences; while highly specific terms proliferated—chemist, mathematician, naturalist—the broad term "philosopher" was no longer satisfactory to group together those who pursued science, without the caveats of "natural" or "experimental" philosopher. Whewell compared these increasing divisions with Somerville's aim of "[rendering] a most important service to science" "by showing how detached branches have, in the history of science, united by the discovery of general principles." Whewell reported in his review that members of the British Association for the Advancement of Science had been complaining at recent meetings about the lack of a good term for "students of the knowledge of the material world collectively." Alluding to himself, he noted that "some ingenious gentleman proposed that, by analogy with artist, they might form [the word] scientist, and added that there could be no scruple in making free with this term since we already have such words as economist, and atheist—but this was not generally palatable". Whewell proposed the word again more seriously (and not anonymously) in his 1840 The Philosophy of the