NOTES 1 19 



and have tried to impress upon my mind in practical 

 ways the principles of action of these three classes of 

 micro-organisms." 



Definitions are said not to define, but who can im- 

 prove upon this one from Kentucky? An infectious 

 disease is "a disease which is contracted from disease 

 germs which make a specialty of this work," and this 

 is as true to facts, although more difficult to read 

 aloud, "Bacteria are infinitely small, intensely ener- 

 getic, enormously prolific protoplasmic micro-organ- 

 isms." 



A little knowledge is not always a dangerous thing. 

 One woman says, "I thought when I took up the first 

 lesson paper that there was nothing in it I should ever 

 understand, but now it looks so different." She had 

 seen molds through a magnifying glass, and goes on 

 to say, "At any other time I wouldn't have given it a 

 look or thought." 



A guide-post which points decidedly in the direction 

 of success reads-. 



"Thank you more than I can say for the severity of 

 your criticisms on the answers I sent. I liked it and 

 because of it feel more confidence in the whole course." 



From Ohio comes this report: "I did find a doctor 

 in our town who .... helped me to see things. 



"I had an idea that the contents of the Petri dish 

 might be viewed at once. . . . The doctor said 

 "Yes, under the focus it would be as large as the state 

 of Ohio." 



