" PRESERVATION BY CANNING. 247 



quantities could be raised. For example: before the beginning of 

 tomato canning, only a very small crop could be utilized; but the 

 opening of this canning industry has entirely changed the conditions, 

 and now great tracts of land can be devoted to raising this delicacy, 

 thus opening to the farmer an entirely new outlet for his crop. The 

 same is true of many another farm product. It is no longer neces- 

 sary for. the farmer to depend upon his own market, but, by the aid 

 of canning, his market may be the world, open to him the whole 

 twelve months of the year. The canning industry makes it possible 

 for the farmer to become a specialist, where it was impossible a 

 few years ago. He may raise green corn, or tomatoes, or straw- 



*{ A * * %*" 



^ -^ % ^ r u 



4\ V jO 



|l 



FIG. 50. Three species of bacteria causing the spoiling of canned corn 

 (Prescott and Underwood}. 



berries as abundantly as he pleases, and whatever he cannot find 

 an immediate market for may be preserved for a later season by the 

 process of canning. It is well for the agriculturist to learn that 

 in farming, as in all other industries, it is the specialist who succeeds, 

 and that the proper utilization of the process of canning is one of 

 the means of making a special product upon a farm yield proper 

 returns. Canning makes possible an intensive farming, undreamed 

 of a few years ago. 



The present condition of the canning industry has been reached 

 only after years of experience, accompanied with many failures and 

 losses. Whole shipments have sometimes been ruined by " swelling," 

 which means that the cans swell out from the force of the putrefying 

 gases forming within. The failure to appreciate the difficulty of 



