PREFACE 



THE course of work described in the following pages forms 

 an introduction to all branches of Natural Science. The ele- 

 mentary nature of the book has caused me to pay more atten- 

 tion to method than to detail. Every student will need to 

 follow closely and thoughtfully the performance of each ex- 

 periment, in nearly all cases making his own observations and 

 measurements, in order that the capacity for independent 

 judgment, as well as an interest in original research, may be 

 awakened at the outset. When a fact or law, discovered by 

 means of a student's own personal observation and intelligence, 

 turns out to be very familiar to others more advanced, the 

 value of the research to the student himself is but slightly 

 impaired. 



Each section conveys a definite lesson, and care has been 

 taken that they may follow in inductive sequence. It is im- 

 portant that each experiment and each stage of the course 

 be described and reviewed at length in the student's note- 

 book, which should contain many practical details omitted 

 from the text-book, not only lest they should obscure the 

 more important outlines of work, but also because it is in- 

 tended that some freedom and originality in manipulation 

 should be encouraged. The trials and practical difficulties of 

 the laboratory are too valuable educationally to be set aside by 

 . over-help, though it is essential that they should not be too 



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