SCIENCE LETTER FROM PARIS. 181 



In the mountainous regions of the Alps and the lura, the cottages are miser- 

 able, they are constructed in wood, covered with green turf, with an aperture at 

 the top for chimney and ventilator. The residents live in an atmosphere of 

 smoke. At the sides of the hut are annexes filled with dry leaves or maize straw; 

 these form the bed-rooms. On an opposite side, the domestic animals are housed, 

 but only for the night. M. Loyet attributes the principal cause of the insolubrity 

 of rural habitations to their defective walls, which permit humidity to enter. The 

 thatched roof he admits may be thick and solid, but it rots quickly, and is the 

 refuge for horrible worms. The earthen floor is objectionable, and wherever one 

 in wood, tiles, or flags can be laid down, it ought first to have a sub-stratum of 

 broken stones and mortar, a concrete bed in fact. 



The dwellings are invariably overcrowded, and the rarity of windows is the 

 natural consequence of the baneful tax on doors and windows. The average 

 ^'openings" per each house-occupant, is for fifty-three more than the one-half of 

 the departments of France, a little above one, and, as this sad condition exists 

 chiefly in the rural districts, disease follows regularly in the wake of habitations 

 so constructed. Respecting manure heaps and foecal drainage, it is the old story. 

 As to the dietary of the peasants, it is very defective ; the bread is too often 

 mouldy; but then there are localities where it is baked for months in advance. 

 Ordinarily the regimen is maize, oat meal, buckwheat and millet, and consumed 

 in the form of porridge. When the grain is diseased, as in the case of ergot rye, 

 the consequences can but be deplorable, but damaged maize produces the malady 

 oipellagre, only second in point of disaster, as Lombardy and Venetiacan testify. 

 In reference to pellagre, misery is not the cause of the scourge, but rather a favora- 

 ble medium for its development. It is unknown among the poor of Ireland and 

 Silesia, and is due, according to Professor Lombraso, to degeneracy of the grain, 

 caused by parasitical mushrooms, and that induce the formation of a toxical alka- 

 loid. 



Being rather accustomed of late to the visits of comets, may explain why no 

 very marked interest is taken in the present visitor. It travels at the daily rate 

 of three miUions of miles, nearly double that of our earth's diurnal rotation round 

 the Sun. Its tail, always foremost, turned toward the Sun, like every comet's, 

 presents the form of a plume of feathers, and is estimated to be 600,000 miles in 

 length. Other comets have had tails from 120,000 to 240,000 miles long. However, 

 the tails are only rays of light, transparent and imponderable. Spectral analysis has 

 shown that carbon and hydrogen are the predominating elements of such luminous 

 volumes ; were they to affect the constitution of our atmosphere, the result would 

 be grave ; a diminution in the proportion of oxygen, would plunge us into a state 

 of heaviness and lethargy, while an augmentation would bring about a condi- 

 tion of exhilaration and nervous excitement, caused by the rapid combustion of 

 the blood in the lungs and arteries, not less fatal. No fear is to be apprehended 

 under the head of a collision, the comet is not a " star of terror." Borne comets 

 have attained one million and a half miles in diameter; that of 181 1 had a tail 



