522 THE POPULAR SCIENCE MONTHLY. 



Our present knowledge of diphtheria depends upon the dis- 

 covery of its specific microbe by Klebs and Loeffler, on the proof 

 that this micro-organism causes diptheria, on the isolation of the 

 diphtheria toxine by Roux and Yersin, and on the discovery of 

 the antitoxine by Behring. An immense field of research spreads 

 out before us ; for example, all but the last-mentioned fact is as 

 true of typhoid fever as of diphtheria, and it is probably a matter 

 of but a few months when physicians will be at work determin- 

 ing the scope of usefulness of a typhoid antitoxine. 



WINDMILLS AND METEOROLOGY. 



By p. J. DE EIDDER. 



THE credit that has been given in all ages to the spirit of ob- 

 servation of sailors is only justice. There are other observ- 

 ers, however, no less sagacious and no less assiduous than sailors, 

 w^hose powers have not been so conspicuously published. These 

 are the millers of windmills. The number of these observers is 

 necessarily diminishing rapidly in our days in consequence of the 

 progressive disappearance of windmills before the advance of 

 steam mills. Yet there are still in the lands of Holland and 

 Flanders a considerable number of these old-fashioned millers, 

 and it has occurred to me to give a few lines to the consideration 

 of the way in which they observe the phenomenq> of the atmos- 

 phere. 



They are real observers, as we shall show. The most intelli- 

 gent of them observe, according to their own rules, all the changes 

 of the weather. Those of a lesser degree of intelligence are satis- 

 fied with noticing the movements of the mills situated farthest in 

 the direction whence the wind comes, and thus regulating the 

 management of their own mills after the example set them by 

 their fellows. These prepossessions of millers concerning the 

 weather should not surprise us, for it is in the line of their direct 

 interest to prognosticate atmospheric changes, and especially to 

 be able to foresee how strong the wind will be, as much for the 

 safety of their mills, which are exposed to all the storms, as in 

 view of keeping on good terms with their customers by properly 

 executing their orders. 



So, after a considerable duration of calm weather, the miller, 

 seeing the cirrus and the cirro-stratus appearing in the south- 

 western horizon, joyfully exclaims : 



"To-morrow the wind will blow 

 And the mill will turn." 



