MANCHESTER NEW COLLEGE. INTRODUCTORY LECTURE, Montage BY. M. L. PHILLIPS, ESQ. PROFESSOR OF PHYSICAL SCIENCE AND NATURAL HISTORY. BEING THE THIRD OF THE SERIES OF INAUGURAL LECTURES DELIVERED BY THE SEVERAL PROFESSORS AT THE OPENING OF THE COLLEGE, IN OCTOBER, 1840. LONDON: SIMPKIN, MARSHALL AND CO. STATIONERS' HALL COURT : AND J. GREEN, NEWGATE STREET. INTRODUCTORY LECTURE TO THE COURSES ON PHYSICAL SCIENCE. GENTLEMEN, I have been requested by the Committee of the College, to deliver an introductory discourse, explanatory of the objects and bearings of that department to which I have had the honour to be appointed; viz. the department of Physical Science, and Natural History. In the course of my duties here, it will devolve upon me to deliver Lectures on Mechanics; Pneumatics; Acoustics: on Heat: on Electricity, under its various forms: on Chemistry: on Hydrostatics and Hydraulics: on Optics: on the Classification of Animals and Vegetables: on Animal and Vegetable Physiology: Structural Botany: on Natural History, and on Geology. This department, you will perceive, includes a range of subjects, the study of which must prove of great interest in itself; and of still greater interest, when considered in its important practical applications to the every-day business of life. In those lectures, which I hope to have the pleasure of delivering at a future period, it will be my main object to render the various subjects as intelligible as possible, by numerous experimental illustrations, preparations, and careful diagrams. Physical Science may be studied in two ways; experimentally, and theoretically: that is, we may arrive at certain conclusions respecting the phenomena of Nature, from the results of a few careful experiments; or we may derive the same consequences from a train of thought, guided by the inductive resources of mathematical knowledge. Theory and practice cannot, however, be entirely separated. Experiment furnishes the data for theory; and theory serves to direct us in our experimental researches. Without theory, there would be no object for experimental research-without experiment, there would be no foundation for theory. In our study of Nature and of Natural Phenomena, we are constantly pressed by the question, "What is the cause of this?" The business of the Natural Philosopher is to unfold those general principles which connect the events of our material world. He assumes as a basis the constancy and permanence of the actual state of things. The appearances which present themselves to his view he terms phenomena; and the common relations which pervade these phenomena he terms laws. To be able to answer the question which may be asked respecting particular phenomena; that is, to be able to explain their cause, he must remount patiently from effects to causes, till he approach the fountain of all power and intelligence; and from this eminence again descend, and trace the chain of consequences. He must employ the two processes of analysis and synthesis. The analysis or investigation of physical facts he conducts either by observation, or by experiment. Observation is the close inspection and attentive examination of those phenomena which arise successively in the course of nature: experiment, as the term implies, (or, as it is better called by the French, experience,) consists in putting questions to nature by a sort of trial, or artificial selection and combination of circumstances, for the purpose of seeing what will be the probable results. The chief business of the philosopher is to notice carefully, and to separate clearly, the various effects which are mingled and confused together in the ordinary concurrence of events. A number of primary facts having been thus extracted by close observation, or from accurate experi ment, the synthetical deduction may be safely pursued by the exercise of a sober and cautious logic. It is only by thus accumulating facts and multiplying observations, that we can ever hope to arrive at correct notions of the machinery of Nature. Suppose a clock fixed against a wall. Imagine a number of persons engaged in contemplating the motions of the two hands. Suppose, moreover, what is conceivable, that they had never seen a clock before. Let us imagine a few to be acquainted with the fundamental truths of mechanics. These last, called upon by their fellows, would endeavour to account for the motions of the hands. One would make a supposition or theory; he would try to explain what was observed upon known mechanical principles. His first hypothesis might perhaps, on trial, be found erroneous, or imperfect. Either it might not give a right reason for the motion of the hands; or it might furnish a correct account of the motion of the minute hand, but leave that of the hour index unexplained. He would make another theory. His second hypothesis might nearly accord with the motions observed. Undaunted by his failure, and encouraged by his apparent success, he tries again, and is rewarded, at last, by the discovery of a mechanical arrangement by which the observed motions may be accurately produced; and this, although neither he nor any other could, by any possible means, arrive at a sight of the works actually employed; concealed for ever from his view by an impenetrable case. Kepler and Newton were two such persons. The heavens their clock; gravitation the spring. Nature is such a clock; we can see the hands, we can even perceive the various parts in motion; we can often distinguish the working geer, but we cannot see the spring which sets the whole in motion. This remains a mystery. By carefully studying those parts submitted to our view; by considering their mutual adaptation and subserviency, we may form some idea, more or less erroneous, about the nature of the prime mover. In the case, as it frequently B |