All topics are welcome to mattoids, even those most foreign to their profession or occupation; but they are found to choose by preference the most grotesque and uncertain subjects, or questions which it is impossible to solve. Such are the quadrature of the circle, hieroglyphics, exposition of the Apocalypse, air-balloons, and spiritualism. They are also fond of treating the subjects most talked of--what one might call the questions of the day. Speaking of Démons, who has already been mentioned, Nodier said, “He was not a monomaniac--very much the contrary; he was a many-sided madman, always ready to repeat any strange thing that came to his ears, a chameleon-like dreamer, who insanely reflected the colours of the moment.”[347] Thus, at the time of our great national deficits, projectors appeared by the dozen, with proposals to restore the Italian finances, either by means of assignats, or by the spoliation of the Jews or the clergy, by forced loans, &c. Later on, came the social and religious problem (Passanante, Lazzaretti, Bosisio, Cianchettini); at the present moment the question most under discussion is that of the _pellagra_. Thus we have, among others, Pari, who has discovered the cause of the disease in certain fungi, which fall from the roofs of dirty huts into the peasants’ food, and make them ill. The proof is evident: photograph the section of a hut, and place it under the microscope, and you will find, on comparison, that fungi are more numerous than in town houses where _pellagra_ is unknown. But why do these fungi produce the _pellagra_? The reason is very simple. These fungi contain the substance _fungina_, which burns at 47° (_sic_). Now, when the outside temperature is at 13° and the body at 32° (_sic_) the two quantities of caloric are added together, and we burn! This is why sufferers from the _pellagra_ appear scorched by the sun! It is noteworthy that in nearly all--Bosisio, Cianchettini, Passanante, Mangione, De Tommasi, B----,--the convictions set forth in their written works are exceedingly deep and firmly fixed. They show as much absurdity and prolixity in their writings as they do common sense and prudence in their verbal answers--even rebutting objections with a single monosyllable, and explaining their own eccentricities with so much good sense and sometimes acuteness that the unlearned may well take their fancies for wisdom; while, later on, they relieve their insane impulses by covering reams of paper.