PREFACE. 



THIS little work is designed to aid teachers who are using 

 the Fourteen Weeks Course. The problems contained in 

 all the books are fully, and, it is thought, accurately solved. 

 Great pains have been taken to revise and compare them 

 carefully. The practical questions are answered, often not 

 in full, yet enough so to give the key to the more perfect 

 reply. The use of the text-books is presupposed, and the 

 statements merely supplement, or apply the fuller theories 

 therein contained and explained. On many points there 

 may be a difference of opinion. The author often finds in 

 his own classes a wide diversity. On mooted questions he 

 has merely advanced one view, leaving the subject open 

 for the discussion of other theories. Minute directions are 

 given, pages 71-82 inclusive, for performing a course of 

 experiments in Chemistry. It is hoped that these may be 

 of service to teachers who, with incomplete apparatus, are 

 trying to illustrate to their pupils some of the principles cf 

 that science. In all cases of doubt or misunderstanding 

 with regard to the answers or solutions, the author will be 

 pleased to correspond with any teacher using the Series 



ELMIRA, March 19, 1870 



