THE MICROSCOPE. 



119 



Contrary to what occurs in moulds, the number of schizophytes, 

 which is small during rainy weather, rises when all the dampness 

 has disappeared from the surface of the soil. The action of dry- 

 ness is greater than that of the temperature. It seems, in fact, as a 

 result of numerous experiments, that the water evaporated from 

 the surface of the soil never carries schizophytes with it. Dry dust, 

 on the contrary, that from hospitals principally, is charged with 

 microbes. As a result of comparative experiments made in Rue 

 Rivoli, and at Montsouris, it appears that the air contains nine times 

 as many bacteria in the interior of Paris as in the vicinity of the 

 fortifications. The influence of the dominant winds is notable. 



*H fl o> 



FIG. II. 



That from the northwest reaches Montsouris laden with a consider- 

 able number of bacteria. This is the wind that blows from the 

 hills of La Villette and Belleville. Then come the winds from the 

 east, north, and northwest. The south wind is less charged with 

 these organisms. The distribution of microbes in a vertical direc- 

 tion indicates that thev are derived from the mud and dirt of the 



J 



streets and dwellings. A cubic meter of air, which contains but 28 

 of them at the summit of the Pantheon, contains 45 at the Park 

 Montsouris and 462 at the Mayoralty of the fourth ward. 



The determination, among these myriads of schizophytes of the 

 air and water, as to which are the ones that intervene in contagious 

 "diseases is the final problem proposed to science,"and the solution 

 of which will be greatly aided by the work that is being done at the 

 observatory under consideration. — The Scientific American from Le 

 Genie Civil. 



