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 
Preparing 
the Soil. 
