PART II.
THE CAUSES OF GENIUS.

CHAPTER I.
Meteorological Influences on Genius.

The influence of weather on the insane—Sensitiveness of men of genius to barometrical conditions—Sensitiveness to thermometrical conditions.

The Influence of Weather on the Insane.—A series of clinical researches, which I carried on for six consecutive years, has shown me with certainty that the mental condition of the insane is modified in a constant manner by barometrical and thermometrical influences.[185] When the temperature rose above 25°, 30°, and 32° C., especially if the rise was sudden, the number of maniacal attacks increased from 29 to 50. On the days on which the barometer showed sudden variations, especially of elevation—and more particularly two or three days before and after the variation—the number of maniacal attacks rapidly increased from 34 to 46. This meteoric sensibility, as I term it, increased in an inverse ratio to the integrity of the nervous tissues, being very great in idiots and slightest in monomaniacs. The study of 23,602 lunatics has shown me that the development of insanity generally coincides with the increase of monthly temperature and with the great barometrical perturbations in September and March; the onset of heat, acts more efficaciously, however, than the intense heat which follows; and the heat which has become habitual in August acts much less harmfully. The minimum number of outbreaks of insanity is found in the coldest months. (See Plate.)

This coincidence is seen best in the French lunatics studied by Esquirol.[186] The French figures present with most clearness the effect of thermometrical influences, because in France the entry of lunatics into asylums, being little impeded by red-tapeism, follows closely on the outbreak.

Month Insane. Temperature. Month Insane. Temperature.
Italy. France. Italy. France.
June 2,704 55 21° 29C. October1,637 44 12° 77C.
May 2,642 58 16° 75C. Sept.1,604 48 19° 00C.
July 2,614 52 23° 75C. Dec.1,529 35 1° 01C.
August 2,261 45 21° 92C. Feb.1,420 40 5° 73C.
April 2,237 50 16° 12C. Jan.1,476 42 1° 63C.
March 1,829 49 6° 60C. Nov.1,452 47 7° 17C.

Now, a similar influence may be noted in those to whom nature, benevolently or malevolently, has conceded the power of intellect more generously than to others. There are few among these who do not confess that their inspiration is strangely subject to the influence of weather. Those who associate with them, or who read their correspondence, know that they suffer so greatly from this cause that they often complain to every one, and struggle, with the help of various artifices, against the malignant influences which impede the free flight of their thought.

Sensitiveness to Barometrical Conditions.—Montaigne wrote: “Si la santé me sied et la clarté d’un beau jour, me voilà honnête homme.” Diderot wrote, “Il me semble que j’ai l’esprit fou dans les grands vents.” Giordani foretold storms two days beforehand.[187] Maine de Biran, a very spiritualistic philosopher, wrote, in his Journal de ma Vie Intime, “I do not know how it is that in bad weather I feel my intelligence and will so unlike what they are in fine weather;” and again, “There are days in which my thought seems to break through the veils which surround it. In some conditions of the weather I feel delight in good, and adore virtue; at other times I am indifferent to everything, even to my duties. Are our sentiments, our affections, our principles, related to the physical condition of our organs?”[188] The study of his Journal shows us the justice of his doubts. Let us take 1818. In April we find two periods of good inspiration and four of bad, although the weather was fine; in May he was constantly sad, and in November only cheerful during ten days.

“1815, May.—I am suffering from the nervous disposition which I experience in spring; and though wishing to do too much, I do nothing....

“23 May.—I am happy because of the air that I breathe and the birds that are singing; but inspiration passes away through the senses. Each season has not merely special forms of sensation, but a certain way of understanding life which is peculiar to it....