DUST GARDENS. 9 



flannel wet in cold water. Squeeze the meat carefully 

 to get out all its juices but not much fat. The meat 

 is acid, therefore, add from one-eighth to one-quarter 

 teaspoonful of bi-carbonate of soda. Replace the water 

 lost through evaporation. 



Moisten three heaping tablespoonfuls of finely di- 

 vided gelatine in a very little cold water and add to 



FIG. 2. SHALLOW BOWL COVERED WITH SHEET OF GLASS. 



the boiling hot broth. When the gelatine is dis- 

 solved, strain through hot flannel. 



Put three or four tablespoonfuls of the broth into 

 each of several small bottles. Plug the mouth of 

 each with a close wad of cotton wool or tie over each 

 a thick mat. of the same. For three successive days 

 place the bottles on a piece of folded cloth in a pan of 

 cold water and boil them fifteen minutes. 



Gelatine melts at quite a low temperature, so if the 

 dust garden is prepared in summer it may not re- 

 main solid. If kept in a very warm place in the 

 room it may melt at any time. A better substance 

 to use for the jelly is agar, which remains solid at blood 

 heat, 98.5 Fahr. This may be found in some cities 

 at the druggists', or at the dealers in chemical or bac- 

 teriological supplies. It solidifies suddenly, if its temper- 

 ture drops below a certain point, and as it is rather 



