PREFACE. V 



that may prove of service to some other teacher. All of 

 the experiments are simple and may be performed by 

 any student. Most of the apparatus is made by the 

 students, and no elaborate pieces are required. The other 

 supplies are such as may be obtained from the ordinary 

 market, or are similar to those found in any simple chem- 

 ical or physical laboratory. 



I have to thank Mr. C. B. Wilson of the State Normal 

 School at Westfield, Mass., and Dr. Theodore Hough of 

 the Massachusetts Institute of Technology, for carefully 

 reading the manuscript and making some valuable sug- 

 gestions. B M B 



BOSTON, MASS., April, 1900. 



