302 



NATURE STUDY REVIEW 



:8— Nov., 1912 



our study of teeth that germs are found in the stuff that gathers 

 between the teeth. We also are told that germs of decay thrive 

 where there is dead stuff and where it is warm, moist, and out of 

 continued direct sunshine. Naturally we might well look for 

 germs on the skin, therefore. If a compound microscope with 

 an oil immersion lens is at hand, and the teacher can make a 

 stained mounting of scrapings from a pupil's skin, the presence 

 of germs can readly be demonstrated. 



(b) In the absence of the microscope, a gelatin culture med- 

 ium, such as is described in the December, 1911, Nature- Study 

 Review, page 274, can be employed. Apply some scrapings 

 from the skin to the medium, and also some bits of decaying 

 organic stuff of any kind, to another part of the medium, and 

 set aside in a rather warm place for two or three days. There 

 will appear colonies of bacteria easily seen with the naked eye. 



Al'l'ARATUS TO DkTECT DECOMPOSITION OF SkIN ReI'USE. 



