Experimental method

“ There are only two modes in which laws of nature can be ascertained--deductively and experimentally; including under the denomination of experimental inquiry, observation as well as artificial experiment. Are the laws of the formation of character susceptible of a satisfactory investigation by the method of experimentation? ”

“ Great deficiencies remain to be supplied, and many vaguely-known points to be cleared up, nor has an effort even been made as yet to systematize all the groups of results gained. The latter task we propose to attempt here, with the purpose of showing by a remarkable instance the manner of evolving knowledge through the power of the experimental method, the sequent, cumulative, and mutually-supporting character of well-conducted experiments, and their endless wealth of instruction; in a word, the process adopted by eminent men in the great art of wresting her secrets from living Nature. ”

“ Everything depends upon the degree with which the characteristic mental states are brought into play under experimental conditions. The great advantage of the experimental method here is, as everywhere, that everything can be varied and changed at will and that the conditions and the effects can be exactly measured. ”

“ The last two examples will have conveyed to any one by whom they have been duly followed, so clear a conception of the use and practical management of three of the four methods of experimental inquiry, as to supersede the necessity of any further exemplification of them. The remaining method, that of Residues, not having found a place in any of the preceding investigations, I shall quote from Sir John Herschel some examples of that method, with the remarks by which they are introduced.
"It is by this process, in fact, that science, in its present advanced state, is chiefly promoted. ”

“ The discoveries which change the method of a science from experimental to deductive, mostly consist in establishing, either by deduction or by direct experiment, that the varieties of a particular phenomenon uniformly accompany the varieties of some other phenomenon better known. ”

“ Analysis of this crude kind does no more than give us our bearings. If we are to lay out the facts with scientific accuracy, we must carry actions into the laboratory, and examine them under experimental conditions. We do this by way of the ‘reaction experiment.’
§ 55. The Reaction Experiment.—The reaction experiment comes to us, of all unlikely things, by the road of astronomy. In the old days, before electrical instruments were invented, astronomers used to time the passage of a star across the meridian of their observatory by means of the eye-and-ear method. ”

“ When we have thus brought together the requisites, both material and intellectual, for a particular experiment, it may sometimes be desirable that before the instruments are dismounted and the observers dispersed, we should make some other experiment, requiring the same method, but dealing perhaps with an entirely different class of physical phenomena. ”

“ I tried out various experiments described in treatises on physics and chemistry, and the results were sometimes unexpected. At times I would be encouraged by a little unhoped-for success, at others I would be in the deepest despair because of accidents and failures resulting from my inexperience. But on the whole, though I was taught that the way of progress is neither swift nor easy, this first trial confirmed in me the taste for experimental research in the fields of physics and chemistry. ”

“ One remarkable feature in the modern progress of biological science has been the application of improved methods of observation and experiment, and the employment in physiological research of the exact measurements employed by the experimental physicist. ”

“ We must, however, refresh ourselves by occasional contact with the solid ground of experiment, and an interesting problem now lies before us awaiting experimental solution. Suppose two hundred men to be scattered equably throughout the length of Pall Mall. ”

“ In one of his later experimental researches he wrote:—
As an experimentalist, I feel bound to let experiment guide me into any train of thought which it may justify; being satisfied that experiment, like analysis, must lead to strict truth if rightly interpreted; and believing also that it is in its nature far more suggestive of new trains of thought and new conditions of natural power. ”

“ The object of experimental philosophy is the knowledge of nature in general, or more strictly, that of the properties of natural substances, and of the changes of those properties in different circumstances. This knowledge can only be attained by experiment, or observation ”

“ The presumption that biological phenomena may be adequately treated in terms of chemistry and physics takes care of itself so far as strict science is concerned, since its utter futility becomes apparent almost immediately it is put to rigid experimental test. ”

“ And it is just such a connection as this which the teacher must seek to establish in all scientific teaching. In experimental science such a connection is most readily established in the mind of the student by means of a series of well [Pg 242] -arranged experiments, which each one repeats for himself at the laboratory table. Obviously, however, it is impossible, in a limited course of teaching, to go over the whole ground of chemistry and physics in this way, or even over that small portion of the ground with which the average scientific student can expect to become acquainted. ”

“ Like observation, experimentation has been wonderfully improved of late years. The experimental sciences which make most use of it—experimental physics, chemistry, physiology, pathology, etc.—have made astounding progress. But it is just as important in the case of experiment—or observation under artificial conditions—as of simple observation that it be undertaken and carried out with a sound and clear judgment. Nature can only give a correct and unambiguous answer to the question you put it when it is clearly and distinctly proposed. ”

“ I have often contemplated taking the experiments in hand myself, but have abandoned them, because my materials did not appear to me sufficiently extensive, and in all such experiments nothing is to be more avoided than a frittering away of experimental materials by a too complicated form of problem. ”

“ The processes of the medical art are even now mostly empirical: their efficacy is concluded, in each instance, from a special and most precarious experimental generalization: but as science advances in discovering the simple laws of chemistry and physiology, progress is made in ascertaining the intermediate links in the series of phenomena, and the more general laws on which they depend ”

“ The practical procedure and practical assumptions of modern experimental science, since they make thinking essentially and not merely accidentally a process of discovery, seem irreconcilable with both the empirical and transcendental interpretations. ”

“ It is true that an experiment, in which the principal aim is to see what happens under certain conditions, may be regarded as an experiment of research by those who are not yet familiar with the result, but in experimental researches, strictly so called, the ultimate object is to measure something which we have already seen—to obtain a numerical estimate of some magnitude. ”

“ Experiment after experiment gave the same result, and I knew, and shrank even as the thought passed through my mind, that in the work I had to do there must be elements which no laboratory could furnish, which no scales could ever measure. ”

“ Experimental thinking, or scientific reasoning, is thus a conjoint process of analysis and synthesis, or, in less technical language, of discrimination and assimilation or identification. The gross fact of water rising when the suction valve is worked is resolved or discriminated into a number of independent variables, some of which had never before been observed or even thought of in connection with the fact. ”

“ Admitting that in certain cases a single experiment in the laboratory is insufficient to reproduce the phenomenon, yet a series of experiments, each of which would be performed to make clear the action of one of the components of the problem, would represent it in its entirety. ”

“ And, although in the study of political economy we can not use that potent method of experiment by artificially produced conditions which is so valuable in the physical sciences, yet, not only may we find, in the diversity of human society, experiments already worked out for us, but there is at our command a method analogous to that of the chemist, in what may be called mental experiment. ”

“ The limitation of our experimental material will make it possible to devote special attention to the scientific principles underlying analysis, to secure a clear and definite grasp of them, and to impart with simple material such experience in the technique and methods of analysis as will train the student to apply both his theoretical and practical knowledge to any field of analysis occasion may require. ”

“ Anyone conversant with a single branch of Natural Science is aware that experiment, as well as observation, is necessary. Who would expect discoveries in physics, or in chemistry, without laboratories and experiments? Do not botanists investigate the functions of plants by dissection, by microscopic and chemical investigation, and by experiment? ”

“ So soon, however, as a result is known to be discoverable, the scientific man ought to proceed to the quantitative inquiry, how great a result follows from a certain amount of the conditions which are supposed to constitute the cause? The possible numbers of experiments are now infinitely great, for every variation in a quantitative condition will usually produce a variation in the amount of the effect. The method of variation which thus arises is no narrow or special method, but it is the general application of experiment to phenomena capable of continuous variation. ”

“ But, when the experiment succeeds properly, we are well rewarded for all the time and trouble bestowed, as by one process carried on in this accurate manner much more just and extensive knowledge is acquired of the nature of the vegetable or animal substance thus submitted to investigation, than by many weeks assiduous labour in the ordinary method of proceeding. ”

“ If you could be persuaded that chemistry can make progress without retorts and balances, that a geologist's hammer is a useless incumbrance, or that engineers can build bridges just as well by the rule of thumb as by the knowledge gained in a workshop, then you might believe that physiology also is independent of experiment. ”

“ Although we cannot always isolate our factors, control our processes, and otherwise apply scientific method, with results as conclusive as those obtained in laboratories of chemistry, physics, or biology, we need not therefore reject scientific method in favor of a rule-of-thumb. ”

“ An essential distinction exists between two stages in the process of advancing our knowledge of the laws of physical phenomena; the first stage consists in observing the relations of phenomena, whether of such as occur in the ordinary course of nature, or of such as are artificially produced in experimental investigations, and in expressing the relations so observed by propositions called formal laws. The second stage consists in reducing the formal laws of an entire class of phenomena to the form of a science; ”

“ In their numerous writings on mechanics, hydrostatics, optics, it is interesting to remark that the solution of a problem is always obtained by performing an experiment, or by an instrumental observation. ”

“ We bring the matter to the test of actual experiment. We make certain experiments, seriatim, upon each of the items that lie within the sentient sphere, and we note the effect which each experiment has upon that portion of the contents which is not meddled with. ”

“ His contribution to the development of science was abstracting the method of experiment from the concrete problem to see its bearing and importance as a universal method of research. He advocated changing education to include studies of the natural world using observation, exact measurement, and experiments. ”

“ It is known to all persons who are conversant in experimental philosophy, that there are many little attentions and precautions necessary to be observed in the conducting of experiments, which cannot well be described in words, but which it is needless to describe, since practice will necessarily suggest them; though, like all other arts in which the hands and fingers are made use of, it is only much practice that can enable a person to go through complex experiments, of this or any other kind, with ease and readiness. ”

“ But to say that physical experiment is either the test, or source, or guide of that other part of philosophy which relates to our internal perceptions, that we are to look in external nature for the form, the substance, the colour, the very life and being of whatever exists in our minds, or that we can only infer the laws which regulate the phenomena of the mind from those which regulate the phenomena of matter, is to confound two things entirely distinct. ”

“ But the mode of simplification adopted in physics and chemistry, viz., experiment, or the arranging of simple artificial conditions, is only to a slight extent applicable to biology. The phenomena are not only complex, but they are so delicately balanced that the introduction of our rude hands in the way of experiment often overthrows the equilibrium, destroys the conditions of biological experiment, viz., life, and thus throws the whole subject into the realm of chemistry and physics. But, fortunately, nature has prepared for us an elaborate series of experiments. ”