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COPYRIGHT, 1915, BY
WILLIAM MCPHERSON AND WILLIAM EDWARDS HENDERSON

ALL RIGHTS RESERVED

515.8

The Athen æum Press
GINN AND COMPANY PRO-
PRIETORS. BOSTON.U.S.A.

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From an educational point of view, chemistry is really the oldest of the experimental sciences. The problem as to what laboratory work should constitute the first year's course is therefore one to which a great deal of thought has been devoted, and many educational experiments have been made in an endeavor to solve it. Much ingenuity has been exercised in the development of suitable laboratory experiments and in the invention of simple apparatus adapted to a beginner's inexperience, and a great wealth of admirable illustrative experiments is now at the command of every teacher.

For one who sets about the task of arranging an experimental course for the beginner, there remains little opportunity for originality or invention. His problem is rather one of selection. Accordingly this laboratory manual lays no claim to originality, either in method or in content. It has been slowly developed in connection with the large beginning classes in which the authors have been interested, and has been revised and reprinted privately a number of times. In response to many requests it has again undergone a thorough revision and has been arranged to accompany the text by the authors, entitled, “A Course in General Chemistry.”

In common with nearly all teachers of chemistry, the authors have had to deal with the fact that the first course in college comprises students who have had an elementary course in the high school, as well as those who have had no earlier introduction to chemistry. As far as the laboratory is concerned, the authors have found that the most practical solution of this problem is to develop a manual ample enough to meet the needs of both classes of students. The

more experienced student can then omit the exercises with which he is familiar, and the student with less experience can omit some of the quantitative exercises.

Every well-ordered laboratory has its own system of supplies, stock solutions, desk reagents, and locker equipment, and the directions in a manual will not always harmonize with this system. For example, in many cases in which the student is directed to prepare solutions or mixtures for specific purposes, it may be much better to have a supply on the side shelf, properly labeled, for general use. In a number of experiments, particularly those involving apparatus that is not a part of the locker equipment, two or even more students may work together to advantage. The time at the disposal of the class will not always permit each student to complete all of the exercises, and variety is added by assigning parallel experiments to alternate students. All such adjustments are left to the instructor.

In the Appendix will be found a number of suggestions to the instructor, relating to the details of special apparatus or reagents. Suggestions are also offered as to a suitable locker equipment and as to the apparatus that the student will need from time to time. Articles may obviously be transferred from one list to another according to the funds available or the capacity of the lockers. A list of the reagents called for in the manual is provided, together with an estimate of the quantities required for a class of ten students.

A large page has been chosen for the manual, since it makes a convenient book for filing in laboratory pigeonholes and for handling during correction. The blank pages can be used for a full record of laboratory observations, or more elaborate reports may be written from the recorded notes if the instructor so desires.

Ohio STATE UNIVERSITY

COLUMBUS, Ohio

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