26 BACTERIA, YEASTS, AND MOLDS 



effectually. The paraffin should be melted in some dish, 

 like a cup, at the lowest temperature at which it will melt, 

 about 140°. The surface of the jelly may then be covered 

 with a thin layer, which will quickly harden. 



These methods of protecting jelly are not sure, and 

 even after sealing it is necessary to keep the jelly in a 

 dry place to insure its keeping properly. Spores may be 

 left under the paraffin, and it is difficult or impossible to 

 seal so that no mold spore can subsequently enter. Jel- 

 lies should therefore be stored in dry closets to keep them 

 from spoiling. If it should happen that no dry closet is 

 convenient, the air in a damp closet may be partly dried by 

 keeping unslaked lime in bowls on shelves near the jelly. 

 These will absorb the moisture and aid in checking the 

 molding. The lime should be renewed from time to time. 



Canned goods will also sometimes mold when the 

 process of canning has not been thorough. This will 

 however be considered later. We must notice here, how- 

 ever, that when cans of fruit are opened and exposed to 

 the air, mold spores are very likely to drop into them, and 

 if they are then shut up again the contents of the can are 

 almost sure to show a fine crop of molds in a few days. 

 It is almost impossible to open a can of fruit, take out a 

 part of it, and close again, without allowing mold spores 

 to drop into it from the air. This must, of course, be 

 guarded against, and if the whole contents of the can can- 

 not be used at once, the part that remains should be boiled 

 and once more closed, as in the original canning. By such 

 heating the spores that may have dropped in while the 

 can was opened are destroyed, and it may be closed and 

 set away safely. 



