CHAPTER XXVIII 
BACTERIA IN SOIL, AIR, WATER, AND MILK 
The nurse who can give relief and comfort to those 
already diseased, and at the same time can protect her¬ 
self and others from becoming infected, is in a true 
sense, capable. To do this, it is important that she not 
only have a knowledge of bacteria after they have gained 
access to the body, but also that she be informed as to 
the means by which these organisms live and are detected 
in other environments. 
The surroundings that are the most vital in sustaining 
life in the human body, and are often the haven for 
harmful bacteria are soil, water, air, and milk. 
Microorganisms of the Soil 
The number and kind of bacteria found in the soil 
are relative, depending largely upon its fertility, cli¬ 
matic conditions, and its relation to plant and animal 
life; as we are interested only in the pathogenic micro¬ 
organisms we can exclude the great list of bacteria and 
molds, which, while not important in this study, are ab¬ 
solutely indispensable in plant life. 
Pathogenic bacteria found in the soil, those giving the 
most trouble are: the B. welchii (gas bacilli), tetanus 
(lockjaw), typhoid bacilli, and spirilla of Asiatic cholera. 
The first two apparently thrive in the soil, the latter, 
unless under very favorable conditions, lie dormant and, 
in a short time, disappear. It is questionable if any 
pathogenic bacteria find the soil their natural habitat 
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