I'RKSKRYATION OF FOOD PRODUCTS FROM BACTERIA. 3! I 



growing when the water falls below 25 per cent. From these 

 facts it follows that anything that can be dried without destroy- 

 ing its value as a food, can, in this way, be effectually protected 

 against bacterial action. No method of preserving food prod- 

 ucts is so universally used as this, and none so effectually. 



In the preservation of the valuable cereal products little is 

 necessary beyond this simple drying. Indeed, here nature 

 herself adopts the same plan, and, when the grain is ripening, 

 the large amount of water which was present in the green seed 

 disappears, leaving the ripened grain, somewhat shriveled per- 

 haps, but with a very small water content. Such a small 

 amount of water does the ripened grain possess that, not only 

 will it refuse to germinate unless moistened with water, but 

 bacteria are utterly unable to grow within it. Nature wishes 

 to preserve the grain through the season of rest (winter) and 

 in order to protect it from bacteria she takes most of the water 

 out, thus preventing the putrefaction which would otherwise 

 surely take place. In harvesting the grain, therefore, all that 

 is necessary for the farmer to do is to collect the product after 

 it is fully ripened, confident that it will not contain enough 

 water to make bacterial growth possible. 



Flesh. With other foods the task is more difficult. The 

 most nutritious food is, in general, the flesh of animals, but 

 this contains so much water that it undergoes decay at very 

 short notice. Such an excellent food for bacteria does this 

 flesh appear to be, and so abundant are the bacteria on every 

 side, that the drying of flesh by simple means is practically 

 impossible. We sometimes read of hunters in the wilds of 

 nature, or of savages, in cooler climates where the air is clear 

 and dry, preserving flesh by the simple process of cutting it 

 into thin strips and hanging it up in the sun to dry. Such a 

 process would hardly suffice upon an ordinary farm, for the 

 flesh would be sure to decay before it became dry enough to 

 resist the action of bacteria. Whether this is due to the 



