of quantitative relations between these facts and the order in which they occur. In this respect physics occupies the great middle ground between pure mathematics, in which the physical facts or axioms are few, and the principles or derived logical relations are the whole content,-and chemistry in which the quantitative logical relations are few and the systematic arrangement of the facts forms the body of the science.
The discovery and the elaboration of the more important physical laws are justly reckoned among the grandest achievements of the human intellect. The character of a discovery, the persons to whom it was due, its philosophical importance, or bearing upon other parts of a science, the representation of the quantitative relations by symbols and the development of still other relations by the application of mathematical analysis, some facility in interpreting such short hand quantitative statements of physical principles, in short, the theory of physics, which is certainly the major part of this science, can best be inculcated by the use of a text-book and recitations. Surely any teaching which does not insist upon the philosophical and quantitative relations, however interesting and brilliant the experiments, or however entertaining the facts presented, or however it busies the student with laboratory exercises, does not teach the science of physics.
But granting that the theory of physics is the backbone of the science, there is no necessity of making it bare bone besides. The lectures should clothe it with flesh and blood. Physics is' not an abstract science like mathematics, and the true physicist objects as much to making physics a mathematical gymnasium as he does to its appropriation as a toy for the kindergarten.
The experimental lecture affords the teacher an opportunity to present and explain to the student under the most favorable conditions the comparatively few important phenomena which he has not already met with. By favorable conditions it is meant that these unfamiliar phenomena often require the use of apparatus so delicate and costly that it is not to be trusted in the hands of any but an expert; or that the matter in question may be so overlaid and obscured by contemporaneous phenomena that the learner can recognize and follow it only with the assistance of a guide. Much also can be explained in the lectures as to the apparatus used for the determination of physical constants and the mode of conducting measurements which has no place in the ordinary text-book, and further the language may be less formal and the mode of presentation may embody much of the personal feeling and enthusiasm of the lecturer, both of which are entirely out of place in a text-book of the principles of a science. There will remain, however, a number of phenomena which, on account of their general minuteness, can not be satisfactorily exhibited in the lectures
