PREFACE 
Ir is the intention of this book to provide a laboratory guide 
for young pupils; a guide which shall introduce them to, and 
give them practice in, method of procedure in laboratory inves- 
tigation. Since the foundation of all science lies in observation, 
the work here given is planned with a view to training and 
developing the power of accurate observation, of critical exami- 
nation, rather than the reasoning processes which depend for 
their results upon the accuracy of the data obtained first through 
observation. 
The child must be taught to see before he is taught to 
explain; he must learn to answer the question what is it? if he 
is ever satisfactorily to answer why is it? He must get his 
mental image clear and complete by using all of his senses upon 
the object before he can understand it, or draw conclusions from 
what he learns. For this reason many of the observations the 
pupil is called upon to make in these lessons bear upon no con- 
clusion. They make no attempt to explain anything, but are 
for the sole purpose of being made. 
For this reason also many observations lead nowhere logic- 
ally, many problems suggested remain unsolved, many whys 
unanswered. For the child this should be so. His work in 
science should leave him with a sense of accomplishment, but 
not of finality. Some whys must be left unanswered to lead 
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