13 



(ii. ) By the Ear. Tap the tin with a pencil or the finger-nails. A high ringing 

 sound is what should result. A dull, dead sound is a warning that all is not 

 well within. 



If the process of sterilization were incomplete or if the tin were insecurely sealed, 

 sooner or later the process of decay begins ; and the effect is to give rise to these 

 external signs and sounds. The contents of such tins are unfit for human food. 



(2.) The Preservation of Food by Suitable Storage. The requirements for this 

 method of protection should be now known to the reader. Food must be kept 

 (a.) Dry; 

 (&.) Cool; 

 (c.) Clean ; 

 (d. ) Protected from the access of decay. 



(Fie. 7.) 



