BACTERIA 



BADEN 



diseases caused by them. When bacteria are 

 to be studied they may be placed in a ttu*k 

 containing some nourishing substance, which 

 must be absolutely free from germs. The dif- 

 ferent kinds of bacteria flourish on different 

 substances for example, blood, potatoes, gela- 

 tin and bouillon and the material must be 

 chosen for the bacteria under consideration. 



After this nourishing material or medium is 

 prepared, and before the bacteria are inserted, 

 it must be sterilized. This is usually done by 

 exposing it to live steam for half an hour or 

 more on several days in succession. When 

 the medium is finally ready the bacteria are 

 placed in the flask, which is then slowly heated 

 until the growth of the bacteria becomes evi- 

 dent. The medium is then allowed to cool, and, 

 if it has been properly prepared, will harden 

 quickly. The bacteria are then held motion- 

 less in the cold gelatin, or whatever the 

 medium may be. Minute specks of bacteria 

 will be seen on the surface of the gelatin. Each 

 speck is a colony of bacteria, and each colony 

 includes only bacteria of a single species. By 

 transferring one of these colonies to another 

 medium, it is possible to raise additional colo- 

 nies of these bacteria indefinitely. These 

 specks or colonies are usually so tiny that it 

 is impossible at first to transfer one and only 

 one. After several such transfers the bacteri- 

 ologist succeeds in getting a growth which is 

 free from all life except the bacteria of a single 

 species. This growth is a "pure culture." 



So minute are many bacteria that no micro- 

 scope is powerful enough to show differences 

 between them. They all have peculiarities of 

 development, however, which can be studied 

 in pun- cultures. For study with microscopes 

 bacteria are usually placed on a glass slide and 

 covered with a piece of thin glass. Some bac- 

 teria are stained, for experiment or for purposes 

 of diagnosis, to bring out their peculiarities; 

 the tuberculosis germs, for example, can be 

 recognized only by their reaction to certain 

 stains. These germs are determined in the 

 following manner: A suspected specimen is 

 stained with a strong solution of a red dye 

 called fuchsin, to which carbolic acid has been 

 added. After staining, the npe< mien is washed 

 in dilute acid, by means of which the stain is 

 U all other bacteria. Notwith- 

 standing the action of the ami. the tutu rmlosis 

 li.irilh retain the red stain, and arc thus dif- 

 ferentiated. W.AJC. 



Consult Mnlr nnd Ritclilo'* Jlfanimf of Bac- 

 teriology; Ball's Eatcntial* of Bacteriology 



BADEN, bah' den, a town in Austria, fifteen 

 miles southwest of Vienna, especially noted for 

 its hot, sulphurous springs. It is visited by 

 more than 20,000 people annually for the sake 

 of its waters, which are believed to have a 

 beneficial effect in cases of rheumatism, gout 

 and kidney and skin diseases. Many mansions 

 are maintained there by the Austrian nobility, 

 among them being the imperial palace of Weil- 

 berg. Its chief industry besides caring for its 

 visitors is the manufacture of small steel tools. 

 To distinguish it from other cities of the same 

 name it is generally called Baden Bei Wien, 

 meaning Baden near Vienna. Population in 

 1910, 14,083. 



BADEN, a famous watering-place at the 

 edge of the Black Forest of Germany, in the 

 Grand Duchy of Baden. It is often called 

 Baden-Baden, to distinguish it from other 

 places of the same name, of which there are 

 many, for the word means baths. From the 

 mineral springs of the town flows water with 

 a temperature which ranges from 117 to 154, 

 famed from very early times. In normal times 

 more than 70,000 people flock to Baden each 

 year seeking relief from gout, rheumatism or 

 diseases of the skin or kidneys, but the : 

 dent population of the town is only 22,000. 



There are a number of attractive buildings, 

 including the grand duke's summer residence 

 and an old castle. The city is arranged in the 

 form of an amphitheater. Aside from caring 

 for visitors, its principle industry is wood- 

 carving. 



BADEN, a former grand duchy of the Ger- 

 man Empire, on the east bank of the Rhine. 

 touching Lake Constance and bordered by 

 Switzerland on the south and Alsace on the 



FORMER 



AUSTRIA-HUNGARY 



THE FORMER GRAND DUCHY 

 west. In size it was the fourth state, and in 

 population the fifth state, in the Kmpii' I 1 -- 



