340 



THE AMERICAN MONTHLY 



[Nov 



Figure 3 is the same section as figure 2, under a higher 

 power. Shows coating of acid-producing and enamel- 

 destroying bacteria, on top of figure; on lower side depth 

 of penetration, stained by eosin. 



I have observed many mouths in which there was no 

 decay, or where decay had ceased ; and occasionally get- 



