PLANTS WHICH CAUSE DECAY 



369 



beef- broth by heating a pound of chopped beef for half 

 an hour (at about 65° C) in a pint of water. Strain it 

 through a cloth, and add two ounces of gelatin (the 

 " sparkling gelatin " used in cooking is preferable) , and 

 let it soak over night. In the morning, heat in the 

 sterilizer until dissolved, then add one-tenth ounce salt 

 (best accomplished by adding one ounce salt to 100 c.c. 

 of water, and taking 10 c.c. of this) 

 and one -fifth ounce peptone (obtain- 

 able at drug- stores; it may be omitted 

 if necessary) , add a tablespoonful of 

 molasses and finish by adding dilute 

 lye or lime-water until the gelatin is 

 slightly alkaline to litmus. Remove 

 the neck from a funnel so that it will 

 fit into a tumbler (Fig. 209), and 

 filter the gelatin through filter paper 

 or cotton, keeping the whole hot in 

 the sterilizer during the process. If 

 the gelatin does not appear clear, 

 filter again, first beating in a little white of ^gg. 

 It may then be placed in a bottle and, the neck be- 

 ing plugged with cotton, sterilized. If necessary, re- 

 peat this for three successive days, when it will keep 

 indefinitely. (Each time the bottle is opened it must 

 be sterilized again.) Now obtain several flat- sided 

 bottles of the same size, and put into each sufficient 

 gelatin to cover the side when the bottle is flat on the 



209. Funnel with neck re- 

 moved so as to fit into 

 a tumbler: the whole 

 is placed in the steri- 

 lizer, in case gelatin 

 is to be filtered hot. 



