214 On the Origin of Aerolites, 



with salt. The salts may therefore be carried by the atmo- 

 spheric air to certain distances. 



In the atmosphere there are frequently miasmata which do 

 not disturb its transparency, and on which our bejt eudiometers 

 have no effect. The experiments which I made with M. La- 

 voisier in the Salpetriere prove this fact beyond all doubt. We 

 took air in a low room, where two hundred women were 

 in bed, the windows of which had been shut for six hours : 

 we compared it, by means of the most accurate eudiometers, with 

 air collected externally, and we found only the same principles ; 

 and yet the smell of the apartment was so infected, that in a very 

 few seconds M. Lavoisier fainted, and the women threatened to 

 break the doors and windows if thev were longer subjected to 

 the disagreeable sensations which thev experienced. 



May not the small-pox and a great many contagious diseases, 

 such as the marsh fever, and the fevers resulting from the pits 

 in which flax has been steeped, be propagated by simple respira- 

 tion ? Here we have another kind of substances, which may be 

 either dissolved, or mixed with the air and carried by it to di- 

 stances which can onlv be limited by the decomposition or al- 

 teration which the substances thus transported undergo. 



If a person remains habitually in a close and damp place 

 filled with newly printed paper, a mortal disease will be the conse- 

 quence. 



We might also cite those showers of insects which probably 

 are brought by the winds, which have either taken up the insects 

 themselves or their eggs ; the showers of corn which we are as- 

 sured have fallen in Spain ; whirlwinds and waterspouts, which 

 frequently carry with them heavy bodies to great heights. 



Bats, foxes, civet-cats, bugs, and various other animals, have 

 a peculiar smell, so strong that it is too easy to perceive when 

 they are near at hand. 



Dogs not only discover animals by the scent, but even their 

 masters. 



In short, it is evident that the combustible bodies, the metals, 

 the metallic, alkaline or earthy salts, essential oils, gases, with 

 animal and vegetable matter in general, may be either dissolved 

 in or mixed with the atmospheric air. 



We may therefore, by analog)^, suppose that the substances 

 generally found in aerolites may be in the same way either dis- 

 solved or suspended in the atmospheric air, in their natural 

 state, the state of oxidation, or the state of salt, and carried 

 to a certain height, either on account of their specific gra- 

 vity in this state of solution or suspension, or on account of 

 ft first impulse, such as the eruption from a volcano, and 



thera 



