Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The following Lessons have been growing into their present form for several years, during which time they have been used in classes under the supervision Of the author. Within the past year they have been revised, with the aim of adapting them to general use. It is confidently hoped that these Lessons will meet a want which is being increasingly felt by teachers and school officers for a suitable text-book to aid them in training the pupils of the upper grammar and lower high school grades to Observe, to think, and to express thought, and in revealing to them some of the laws in accordance with which physical changes occur. It has been the author's aim to guide the investigations of the learner by directions and questions so definite that he will generally be able to get the points desired without aid. Occasionally a question is asked which only a small proportion Of the class may be able to answer; but the question should at least secure the attention of all, and prepare them to grasp the truth when it comes; and the closer workers will get the exercise which they need.

The following Lessons have been growing into their present form for several years, during which time they have been used in classes under the supervision Of the author. Within the past year they have been revised, with the aim of adapting them to general use. It is confidently hoped that these Lessons will meet a want which is being increasingly felt by teachers and school officers for a suitable text-book to aid them in training the pupils of the upper grammar and lower high school grades to Observe, to think, and to express thought, and in revealing to them some of the laws in accordance with which physical changes occur. It has been the author's aim to guide the investigations of the learner by directions and questions so definite that he will generally be able to get the points desired without aid. Occasionally a question is asked which only a small proportion Of the class may be able to answer; but the question should at least secure the attention of all, and prepare them to grasp the truth when it comes; and the closer workers will get the exercise which they need.