46 BACTERIA, YEASTS, AND MOLDS 



have sufficient air. Hence if the seal is good they will not 

 grow on the jelly even though spores are present under thie 

 paraffin. This is the reason why tumblers of jelly can be 

 allowed to stand overnight to harden before pouring on 

 the paraffin. 



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 are often 

 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 

 be considered in a later chapter. We must notice here, 

 however, 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. This must, of course, be guarded against, 

 and if the whole contents of the can cannot 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. 



