great heat, as with insanity also; in the same way the months of greatest barometric variation have an advantage over very hot and very cold months. If we now group these data according to seasons, which will allow us to include other data in which the exact month cannot be stated, we shall find that the maximum of artistic and literary creation falls in spring, 388; then comes summer, with 347; then autumn, 335; and lastly, winter, with 280. The majority of great physical, chemical, and mathematical discoveries took place in spring, 22; then autumn, 15; very few in summer, 10; and only five in winter. I have separated astronomical discoveries from physical, and other discoveries, because their precise dates are less doubtful and therefore more important. We find 135 in autumn; 131 in spring; 120 in summer; and only 83 in winter. Taking these 1,871 great discoveries altogether, we find spring coming first, with 541; then autumn, with 485; with 477 in summer; and 368 in winter. It is evident, then, that the first warm months distinctly predominate in the creations of genius, as well as in organic nature generally, although the question cannot be absolutely resolved on account of the scarcity of data, as regards both quantity and quality. It was, however, in the spring that the discovery of America was conceived, as well as galvanism, the barometer, the telescope, and the lightning conductor; in the spring, Michelangelo had the idea of his great cartoon, Dante of his _Divina Commedia_, Leonardo of his book on light, Goethe of his _Faust_; it was in the spring that Kepler discovered his law, that Milton conceived his great poem, Darwin his great theory, and Wagner the _Fliegende Holländer_, the first of his great music dramas. It may be added that in the few cases in which we may follow, day by day, the traces of the works of great men, we usually find that their activity increases in the warm months and decreases in the cold months. Thus in Spallanzani’s journals, and especially during the years 1777-78 and 1780-81, in which he was undertaking his investigations into moulds, digestion, and fecundation, I found 50 days of observation in March, 65 in April, 143 in May, 41 in June, 33 in August, 24 in September; while there were only 17 in December, 10 in November, 18 in January, 17 in July, and 2 in February. If we examine the curious journal of his own observations, which Malpighi kept day by day for thirty-four years, we find, grouping the observations according to months, July coming first with 71 days, followed by June with 66, May 42, October 40, January 36, September 34, April 33, March 31, August 28, November 20, December 13.[225] Out of over four hundred observations less than a fifth took place in the winter months.