PART IV 
RELATION OF MICROORGANISMS TO MISCELLA- 
NEOUS FARM PRODUCTS 
CHAPTER XV 
ALCOHOL, VINEGAR, SAUER KRAUT, TOBACCO, SILAGE, 
FLAX 
Although the problems of soil fertility and dairying offer the 
largest field for the application of bacteriology to farm life, there 
are many other problems of minor importance where microorgan- 
isms play a part. Most of these concern food products, either 
their preparation or preservation, although some have no relation 
to foods. 
In all temperate and cold climates it is necessary to preserve 
food for the winter season. This applies equally to the farmer’s 
own food and to that of his cattle. There is a difficulty in preserv- 
ing some kinds of food because of the readiness with which putre- 
factive bacteria cause their disintegration and decay. Bacteria 
will feed upon almost any kind of organic matter, provided there is 
plenty of moisture at hand; but some of the foods, like most grains, 
have such a small amount of water in them that bacteria are unable 
to grow, and there is little difficulty in preserving these for an in- 
definite length of time. Nature herself, at the end of the growing 
season, extracts the water from the seeds, leaving the compara- 
tively dry mass to remain over the period of 1est until the growing 
time comes again (Fig. 45). Other kinds of food contain a large 
amount of water, and the farmer must find some means of protect- 
ing such food from bacterial action. This is accomplished in a 
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