66 
MANUAL OF NATURE STUDY. 
absorbents and carried into the structure of the 
muscle or bone ? 
After the food is sucked up where is it conveyed ? 
To the blood vessels. What is the liquid part of 
the blood? Could new food be carried by these 
blood vessels to the lungs and all parts of the sys¬ 
tem, if there were no water in the vessels ? Could 
new food be carried into the muscles, be made over 
into muscle, to the bones and be made over into 
bone, without water ? No more than a plasterer 
can plaster a house without water. Then what 
must be the use of water to our bodies ? Lead the 
pupils to see that as the great bulk of everything 
we eat is water, it will not be necessary to drink so 
very much nor so very often. Frequent drinking 
is often a mere habit, and ought to be avoided. 
Care should be taken not to drink from the shallow 
wells in town as they may be more or less contamina¬ 
ted with the privies and other dangerous wastes of 
the city. Surface wells and foul cisterns should be 
avoided as carefully as you would shun smallpox 
or any other deadly poison. Thoroughly filtered 
water is the only safe kind, and then it is not safe 
if the filter is allowed to become foul. Water 
should also be used for bathing purposes. Soft 
water is recommended for that purpose. Here, 
again, purity should be sought for, because the 
