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 falsity 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. ($1. 25, postage 
12c.) 
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 microscopa 
a drop of the brownish infusion. 
Make any experiments possible from “Bacteria, Yeasts, and 
Molds,” by H. W. Conn, pages 269-285. 
