SCIENCE IN ITS APPLICATION. 95 



Not only does this great world of organisms, hover- 

 ing unseen about us, bristle with enemies to man 

 and his friends, the domestic plants and animals, but 

 among these enemies are numerous active, friendly spe- 

 cies, contributing much to our wealth and comfort. 

 Thus, vinegar, one of our most important condiments, 

 is made only through the agency of the acetic ferment ; 

 alcohol, a source of fearful injury from its misuse, yet 

 invaluable in science and the arts, is made by the action 

 of the yeasts ; clover, the hope of the despairing farmer, 

 owes its soil-enriching power to a humble parasitic bac- 

 terium which seizes its roots for a home ; and the finer 

 flavors of the most aromatic butter are traced to the prod- 

 ucts of the action of particular species of bacteria in the 

 ripening cream. 



OFFICE OF BACTERIA IN CURING TOBACCO. 



Turning now to the consideration of the influence 

 of bacteria in tobacco culture, we omit all reference to 

 the fungous diseases to which the growing plant is sub- 

 ject, and confine attention to the relations of these or- 

 ganisms to the processes of curing and sweating. As 

 the result of these processes, instead of the green color, 

 rough, hard surface, brittle web, black ash, dark, tarry, 

 ill-smelling smoke and bitter, burning flavor possessed 

 by a quickly dried tobacco leaf, the leaves have a beau- 

 tiful brown color, silky texture, elastic web, light blue 

 and pleasantly aromatic smoke, a white or gray ash, and 

 little of the unpleasant flavor of the green leaf. 



A very large fraction of these changes in quality is 

 wrought during the first of these processes, the curing. 

 Despite the fact that the Germans term it das Trocknen, 

 or drying, it is neither a simple physical process, nor a 

 purely chemical one. The results of late studies by 

 Muller-Thurgau * and Dr. J. Behrens, f show that dur- 



Landwirthschaftliches Jahrbuch, 14, 485-512. 



t Landwirthschaf tliclie Versuchs-Stationen, 43, 280-293. 



