158 HOUSEHOLD BACTERIOLOGY 



(f) Touch the fingers to the jelly after handling dusty books. 



(g) Touch the jelly with pieces of money or with a bill. 

 (h) Take any one of the planted plates. Lay over one-half 



of the jelly a thick piece of black paper or cloth. Put 



the dish in direct sunlight, 

 (i) Scrape a bit of the deposit from the teeth and touch 



it to several places on the jelly, 

 (j) Rub a few drops of boiled water in the palm of the hand 



and mix it with the liquefied media. 

 (k) Take one of the dishes to a public gathering and open it 



for five minutes or more when the audience has been 



seated for a short time. 



Require that each experimenter keep a daily record of 

 every change, however minute. At the next meeting let 

 these experiments be reported, the gardens shown, and as 

 many conclusions drawn as may be feasible, leaving their 

 truth or fakity to be proved by further study. 



References: Dust and Its Dangers, by T. M. Prudden. 



Chapters I, II, III, IV. (75C., postage 6c.) 

 Our Secret Friends and Foes, by Percy F. 

 Frankland. Chapters I -III. ($i. 25, postage 



I2C.) 



MEETING II 



(Study pages 17-32) 

 Character of Bacteria 



If possible, get some physician to show bacteria under a 

 microscope. 



(a) Take some from the dust gardens already planted. 



(b) Take a drop of water from a vase of flowers which has 



stood unchanged for a week. 

 Put a wisp of hay in warm water, let it stand for twenty-four 



hours in a warm place, then examine with the microscope 



a drop of the brownish infusion. 

 Make any experiments possible from "Bacteria, Yeasts, and 



Molds,'! by H. W. Conn, pages 269-285. 



