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A Discourse introductory to a Course of Lectures on Chemistry, Delivered in the Theatre of the Royal Institution, on the 21st of January, 1802.

in The Collected Works of Sir Humphry Davy, ed. John Davy (London: Smith, Elder and Co., 1839) II, [307]-26.




[The introductory lecture which follows, and the syllabus of lectures of which it formed a part, with the outlines of a course of lectures on chemical philosophy, are selected for insertion in this portion of the Author's Works on account both of the time in which they appeared and their nature and object. In point of time, they belong to his early productions; and are as characteristic of his scientific youth, with its enthusiasm and vigor, as his essays were of his infancy in science. -- Designed by him for an audience supposed to be ignorant of chemistry; and yet enlightened and refined, for the purpose of rousing attention, and exciting an interest, and giving elementary knowledge, they appear well adapted to answer the same purposes to readers of a similar class, and to introduce those who are not well instructed in chemistry to his other and less elementary writings, which will follow. To chemical readers it is hoped, they may not be unacceptable, as historical sketches of the then state of the science just on the eve of a great revolution, mainly owing to his labours.]





I am induced to publish the following discourse in consequence of the request of a part of the audience before whom it was delivered, the accuracy of whose judgment it would be presumptuous in me to question. It was not originally intended for the press. The subject is too important and sublime to be justly treated in an occasional composition; and the views I have taken were designed rather to excite feelings of interest concerning it, than to give minute information.

26th April, 1802.

Chemistry is that part of natural philosophy which relates to those intimate actions of bodies upon each other, by which their appearances are altered, and their individuality destroyed.

This science has for its objects all the substances found upon our globe. It relates not only to the minute alterations in the external world, which are daily coming under the cognizance of our senses, and which in consequence, are incapable of affecting the imagination, but likewise to the great changes, and convulsions in nature, which, occurring but seldom, excite out curiosity, or awaken our astonishment.

The phænomena of combustion, of the solution of different substances in water, of the agencies of fire; the production of rain, hail, and snow, and the conversion of dead matter into living matter by vegetable organs, all belong to chemistry; and, in their various and apparently capricious appearances, can be accurately explained only by an acquaintance with the fundamental and general chemical principles.

Chemistry, considered as a systematic arrangement of facts, is of later origin than most of the other sciences; yet certain of its processes and operations have been always more or less connected with them; and, lately, by furnishing new instruments and powers of investigation, it has greatly contributed to increase their perfection, and to extend their applications.

{312} Mechanical philosophy, regarded as the science of the motions of the masses of matter, in its theories and practices, is, to a certain extent, dependent upon chemical laws. How in fact can the mechanic calculate with accuracy upon the powers of solids, fluids, or gases, in communicating motion to each other, unless he is previously acquainted with their particular chemical affinities, or propensities to remain to remain disunited, or to combine? It is to chemistry that he is indebted for the knowledge of the nature and properties of the substances he employs; and he is obliged to that science for the artificial production of the most powerful and most useful of his agents.

Natural history and chemistry are attached to each other by very intimate ties. For while the first of these sciences treats of the general external properties of bodies, the last unfolds their internal constitution and ascertains their intimate nature. Natural history examines the beings and substances of the external world, chiefly in their permanent and unchanging forms; whereas chemistry by studying them in the laws of their alterations, developes and explains their active powers and the particular exertions of those powers.

It is only in consequence of chemical discoveries that that part of natural history which relates to mineral substances has assumed the form of a science. Mineralogy, at a period not very distant from the present, consisted merely of a collection of terms badly arranged, according to certain vague external properties of substances. It is now founded upon a beautiful and methodical classification; and that chiefly in consequence of the comparison of the intimate composition of the bodies it represents with their obvious forms and {313} appearances. The mind of the mineralogist is no longer perplexed by endeavours to discover the loose and varying analogies between the colours, the shapes, and the weights of different substances. By means of the new method of analysis, he is furnished with instruments of investigation immediately applicable, and capable of producing uniform and accurate results.

Even botany and zoology as branches of natural history, though independent of chemistry as to their primary classification, yet are related to it so far as they treat of the constitution and functions of vegetables and animals. How dependent in fact upon chemical processes are the nourishment and growth of organized beings; their various alterations of form, their constant production of new substances, and finally their death and decomposition, in which nature seems to take unto herself those elements and constituent principles, which for a while she had lent to a superior agent as the organs and instruments of the spirit of life!

And in pursuing this view of the subject, medicine and physiology, those sciences which connect the preservation of the health of the human being with the abstruse philosophy of organized nature, will be found to have derived from chemistry most of their practical applications, and many of the analogies which have contributed to give to their scattered facts order and systematic arrangement. The art of preparing those substances which operate powerfully upon animal bodies, and which according to their different modes of exhibition are either efficient remedies or active poisons, is purely chemical. Indeed the want of an acquaintance with scientific principles in the processes of pharmacy has often been productive of dangerous consequences; and the study of the simple {314} and unvarying agencies of dead matter ought surely to precede investigations concerning the mysterious and complicated powers of life. Knowing very little of the laws of his own existence, man has nevertheless derived some useful information from researches concerning the nature of respiration; and the composition and properties of animal organs even in their dead state. And if the connection of chemistry with physiology has given rise to some visionary and seductive theories; yet even this circumstance has been useful to the public mind in exciting it by doubt, and in leading it to new investigations. A reproach, to a certain degree just, has been thrown upon those doctrines known by the name of the chemical physiology; for in the applications of them, speculative philosophers have been guided rather by the analogies of words than of facts. Instead of slowly endeavouring to lift up the veil concealing the wonderful phænomena of living nature; full of ardent imaginations, they have vainly and presumptuously attempted to tear it asunder.

Though astronomy in its sublime views, and its mathematical principles, is far removed from chemistry, yet to this science it is indebted for many of its instruments of experiments. The progress of the astronomer has been in some measure commensurate with that of the chemical artist, who, indeed, by his perfection of the materials used for the astronomical apparatus, has afforded to the investigating philosopher the means of tracing the revolutions of the planets, and of penetrating into space, so as to discover the forms and appearances of the distant parts of the universe.

It would be unnecessary to pursue this subject to a greater extent. Fortunately for man, all the different parts of the human mind are possessed of certain harmonious relations; and it is even difficult to draw the line for their objects only dead and living nature, and as they consist of expressions of facts more or less analogous, they must all be possessed of certain ties of connection, and of certain dependencies on each other. The man of true genius who studies science in consequence of its application, -- pointing out to himself a definite end, will make use of all the instruments of investigation which are necessary for his purposes; and in the search of discovery, he will rather pursue the plans of his own mind than be limited by the artificial divisions of language. Following extensive views, he will combine together mechanical, chemical, and physiological knowledge, whenever this combination may be essential; in consequence his facts will be connected together by simple and obvious analogies, and in studying one class of phænomena more particularly, he will not neglect its relations to other classes.

But chemistry is not valuable simply in its connections with the sciences, some of which are speculative and remote from out habitual passions and desires; it applies to most of the processes and operations of common life; to those processes on which we depend for the gratification of our wants, and which in consequence of their perfection and extension by means of scientific principles, have become the sources of the most refined enjoyments and delicate pleasures of civilized society.

Agriculture, to which we owe our means of subsistence, is an art intimately connected with chemical science. For though the common soil of the earth will produce vegetable food, yet it can only be made to produce it in the greatest quantity, and of the best quality, {316} in consequence of the adoption of methods of cultivation dependent upon scientific principles. The knowledge of the composition of soils, of the food of vegetables, of the modes in which their products must be treated, so as to become fit for the nourishment of animals, is essential to the cultivation of land; and his exertions are profitable and useful to society, in proportion as he is more of a chemical philosopher. Since, indeed, this truth has been understood, and since the importance of agriculture has been generally felt, the character of the agriculturist has become more dignified and more refined. No longer a mere machine of labour, he has learned to think and to reason. He is aware of his usefulness to his fellow-men; and he is become at once the friend to nature and the friend of society.

The working of metals is a branch of technical chemistry; and it would be a sublime though a difficult task to ascertain the effects of this art upon the progress of the human mind. It has afforded to man the powers of defence against savage animals; it has enabled him to cultivate the ground, to build houses, cities, and ships, and to model much of the surface of the earth after his own imaginations of beauty. It has furnished instruments connected not only with his sublime enjoyments, but likewise with his crimes and his miseries; it has enabled him to oppress and destroy, to conquer and protect.

The arts of bleaching and dyeing, which the habits and fashions of society have made important are purely chemical. To destroy and produce colours, to define the causes of the changes they undergo, and to exhibit the modes in which they may be rendered durable, demand an intimate acquaintance with chemistry. The artist who merely labours with his hands, is obliged to {317} theory for his discovery of the most useful of his practices; and permanent and brilliant ornamental colours which rival the most beautiful tints of nature, are artificially composed from their elements by means of human inventions.

Tanning and the preparation of leather are chemical processes, which, though extremely simple, are of great importance to society. The modes of impregnating skin with the tanning principle of the vegetable kingdom, so as to render it strong and insoluble in water, and the methods of preparing it for this impregnation have been reduced to scientific principles. And if the improvements resulting from new investigations have not been uniformly adopted by manufacturers, it appears to be owing rather to the difficulty occurring in inducing workmen to form new habits, to a want of certain explanations of the minutiae of the operations, and perhaps in some measure to the common prejudice against novelties, than to any defect in the general theory of the art as laid down by chemical philosophers, and demonstrated by their experiments.

But amongst the chemical arts, few perhaps are more important than those of porcelain and glass making. To them we owe many of those elegant vessels and utensils which have contributed to the health and delicacy of civilized nations. They have furnished instruments of experiments for most of the sciences, and consequently have become the remote causes of some of the discoveries made in those sciences. Without instruments of glass, the gases could never have been discovered, or their combinations ascertained; the minute forms and appearances of natural objects could not have been investigated; and, lastly, the sublime {318} researches of the moderns concerning heat and light would have been wholly lost to us.

This subject might be much enlarged upon; for it is difficult to examine any of our common operations or labours without finding them more or less connected with chemistry. By means of this science man has employed almost all the substances in nature either for the satisfaction of his wants or the gratification of his luxuries. Not contented with what is found upon the surface of the earth, he has penetrated into her bosom, and has even searched the bottom of the ocean for the purpose of allaying the restlessness of his desires, or of extending and increasing his power. He is to a certain extent ruler of all the elements that surround him, and he is capable of using not only common matter according to his will and inclinations, but likewise of subjecting to his purposes the ethereal principles of heat and light. By his inventions they are elicited from the atmosphere; and under his control they become, according to circumstances, instruments of comfort and enjoyment, or of terror and destruction.

To be able indeed to form an accurate estimate of the effects of chemical philosophy, and the arts and sciences connected with it, upon the human mind, we ought to examine the history of society, to trace the progress of improvement, or more immediately to compare the uncultivated savage with the being of science and civilization.

Man, in what is called a state of nature, is a creature of almost pure sensation. Called into activity only by positive wants, his life is passed either in satisfying the cravings of the common appetites, or in apathy, or in slumber. Living only in moments he calculates but little on futurity. He has no vivid feelings of hope, or {319} thoughts of permanent and powerful action. And unable to discover causes, he is either harassed by superstitious dreams, or quietly and passively submissive to the mercy of nature and the elements. How different is man informed through the beneficence of the Deity, by science and the arts! Knowing his wants, and being able to provide for them, he is capable of anticipating future enjoyments, and of connecting hope with an infinite variety of ideas. He is in some measure independent of chance or accident for his pleasures. Science has given to him an acquaintance with the different relations of the parts of the external world; and more than that, it has bestowed upon him powers which may be almost called creative; which have enabled him to modify and change the beings surrounding him, and by his experiments to interrogate nature with power, not simply as a scholar, passive and seeking only to understand her operations, but rather as a master, active with his own instruments.

But, though improved and instructed by the sciences, we must not rest contented with what has been done; it is necessary that we should likewise do. Our enjoyment of the fruits of the labours of former times should be rather an enjoyment of activity than of indolence; and, instead of passively admiring, we ought to admire with that feeling which leads to emulation.

Science has done much for man, but it is capable of doing still more; its sources of improvement are not yet exhausted; the benefits that it has conferred ought to excite our hopes of its capability of conferring new benefits; and in considering the progressiveness of our nature, we may reasonably look forward to a state of greater cultivation and happiness than that we at present enjoy.

{320} As a branch of sublime philosophy, chemistry is far from being perfect. It consists of a number of collections of facts connected together by different relations; but as yet it is not furnished with a precise and beautiful theory. Though we can perceive, develope, and even produce, by means of our instruments of experiment, an almost infinite variety of minute phænomena, yet we are incapable of determining the general laws by which they are governed; and in attempting to define them, we are lost in obscure, though; subtime imaginations concerning unknown agencies. That they may be discovered, however, there is every reason to believe. And who would not be ambitious of becoming acquainted with the most profound secrets of nature, of ascertaining her hidden operations, and of exhibiting to men that system of knowledge which relates so intimately to their own physical and moral constitution?

The future is composed merely of images of the past, connected in new arrangements by analogy, and modified by the circumstances and feelings of the moment; our hopes are founded upon our experience; and in reasoning concerning what may be accomplished, we ought not only to consider the immense field of research yet unexplored, but likewise to examine the latest operations of the human mind, and to ascertain the degree of its strength and activity.

At the beginning of the seventeenth century very little was known concerning the philosophy of the intimate actions of bodies on each other; and before this time, vague ideas, superstitious notions, and inaccurate practices, were the only effects of the first efforts of the mind to establish the foundations of chemistry. Men either were astonished and deluded by their first inventions so as to become visionaries, and to institute {321} researches after imaginary things, or they employed them as instruments for astonishing and deluding others, influenced by their dearest passions and interests, by ambition, or the love of money. Hence arose the dreams of alchemy concerning the philosopher's stone, and the elixir of life. Hence, for a long while the other metals were destroyed or rendered useless by experiments designed to transmute them into gold; and for a long while the means of obtaining earthly immortality were sought for amidst the unhealthy vapours of the laboratory. These views of things have passed away, and a new science has gradually arisen. The dim and uncertain twilight of discovery, which gave to objects false or indefinite appearances, has been succeeded by the steady light of truth, which has shown the external world in its distinct forms, and in its true relations to human powers. The composition of the atmosphere, and the properties of the gases, have been ascertained; the phænomena of electricity have been developed; the lightnings have been taken from the clouds; and lastly, a new influence has been discovered, which has enabled man to produce from combinations of dead matter effects which were formerly occasioned only by animal organs.

The human mind has been lately active and powerful; but there is very little reason for believing that the period of its greatest strength is passed; or even that it has attained its adult state. We find in all its exertions not only the health and vigour, but likewise the awkwardness of youth. It has gained new powers and faculties, but it is as yet incapable of using them with readiness and efficacy. Its desires are beyond its abilities; its different parts and organs are not firmly knit together, and they seldom act in perfect unity.

{322} Unless any great physical changes should take place upon the globe, the permanency of the arts and sciences is rendered certain, in consequence of the diffusion of knowledge by means of the invention of printing; and those words which are the immutable instruments of thought, are become the constant and widely-diffused nourishment of the mind, the preservers of its health and energy. Individuals, in consequence of interested motives or false views, may check for a time the progress of knowledge; moral causes may produce a momentary slumber of the public spirit; the adoption of wild and dangerous theories, by ambitious or deluded men, may throw a temporary opprobrium on literature; but the influence of true philosophy will never be despised; the germs of improvement are sown in minds even where they are not perceived, and sooner or later the spring-time of their growth must arrive.

In reasoning concerning the future hopes of the human species, we may look forward with confidence to a state of society in which the different orders and classes of men will contribute more effectually to the support of each other than they have hitherto done. This state indeed seems to be approaching fast; for in consequence of the multiplication of the means of instruction, the man of science and the manufacturer are daily becoming more nearly assimilated to each other. The artist who formerly affected to despise scientific principles, because he was incapable of perceiving the advantages of them, is now so far enlightened, as to favour the adoption of new processes in his art, whenever they are evidently connected with a diminution of labour. And the increase of projectors, even to too great an extent, demonstrates the enthusiasm of the public mind in its search after improvement. {323} The arts and sciences also are in a high degree cultivated, and patronized by the rich and privileged orders. The guardians of civilization and of refinement, the most powerful and respected part of society, are daily growing more attentive to the realities of life; and, giving up many of their unnecessary enjoyments in consequence of the desire to be useful, are becoming the friends and protectors of the labouring part of the community. The unequal division of property and of labour, the difference of rank and condition amongst mankind, are the sources of power in civilized life, its moving causes, and even its very soul; and in considering and hoping that the human species is capable of becoming more enlightened and more happy, we can only expect that the great whole of society should be ultimately connected together by means of knowledge and the useful arts; that they should act as the children of one great parent, with one determinate end, so that no power may be rendered useless, no exertions thrown away. In this view we do not look to distant ages, or amuse ourselves with brilliant, though delusive dreams concerning the infinite improveability of man, the annihilation of labour, disease, and even death. But we reason by analogy from simple facts. We consider only a state of human progression arising out of its present condition. We look for a time that we may reasonably expect, for a bright day of which we already behold the dawn.

So far our considerations have been general; so far we have examined chemistry chiefly with regard to its great agency upon the improvement of society, as connected with the increasing perfection of the different branches of natural philosophy and the arts. At present it remains for us only to investigate the effects of {324} the study of this science upon particular minds, and to ascertain its powers of increasing that happiness which arises out of the private feelings and interests of individuals.

The quantity of pleasure which we are capable of experiencing in life appears to be in a great measure connected with the number of independent sources of enjoyment in our possession. And though one great object of desire, connected with great exertions, must more or less employ the most powerful faculties of the soul; yet a certain variety of trains of feeling and of ideas is essential to its health and permanent activity. In considering the relations of the pursuit of chemistry to this part of our nature, we cannot but perceive that the contemplation of the various phænomena in the external world is eminently fitted for giving a permanent and placid enjoyment to the mind. For the relations of these phænomena are perpetually changing; and consequently they are uniformly obliging us to alter our modes of thinking. Also the theories that represent them are only approximations to truth; and they do not fetter the mind by giving to it implicit confidence, but are rather the instruments that it employs for the purpose of gaining new ideas.

A certain portion of physical knowledge is essential to our existence; and all efficient exertion is founded upon an accurate and minute acquaintance with the properties of the different objects surrounding us. The germ of power indeed is native; but it can only be nourished by the forms of the external world. The food of the imagination is supplied by the senses, and all ideas existing in the human mind are representations of parts of nature accurately delineated by memory, or tinged with the glow of passion, and formed into new {325} combinations by fancy. In this view researches concerning the phænomena of corpuscular action may be said to be almost natural to the mind, and to arise out of its instinctive feelings. The objects that are nearest to man are the first to occupy his attention: from considering their agencies on each other he becomes capable of predicting effects; in modifying these effects he gains activity; and science becomes the parent of the strength and independence of his faculties.

The appearances of the greater number of natural objects are originally delightful to us, and they become still more so, when the laws by which they are governed are known, and when they are associated with ideas of order and utility. The study of nature, therefore, in her various operations must be always more or less connected with the love of the beautiful and sublime; and in consequence of the extent and indefiniteness of the views it presents to us, it is eminently calculated to gratify and keep alive the more powerful passions and ambitions of the soul, which, delighting in the anticipation of enjoyment, is never satisfied with knowledge; and which is as it were nourished by futurity, and rendered strong by hope.

In common society, to men collected in great cities, who are wearied by the constant recurrence of similar artificial pursuits and objects, and who are in need of sources of permanent attachment, the cultivation of chemistry and the physical sciences may be eminently beneficial. For in all their applications they exhibit an almost infinite variety of effects connected with a simplicity of design. They demonstrate that every being is intended for some definite end or purpose. They attach feelings of importance even to inanimate objects; and they furnish to the mind means of obtaining {326} enjoyment unconnected with the labour or misery of others.

To the man of business, or of mechanical employment, the pursuit of experimental research may afford a simple pleasure, unconnected with the gratification of unnecessary wants, and leading to such an expansion of the faculties of the mind as must give to it dignity and power. To the refined and fashionable classes of society it may become a source of consolation and of happiness, in those moments of solitude, when the common habits and passions of the world are considered with indifference. It may destroy diseases of the imagination, owing to too deep a sensibility; and it may attach the affections to objects, permanent, important, and intimately related to the interests of the human species. Even to persons of powerful minds, who are connected with society by literary, political, or moral relations, an acquaintance with the science that represents the operations of nature cannot be wholly useless. It must strengthen their habits of minute discrimination; and by obliging them to use a language representing simple facts, may tend to destroy the influence of terms connected only with feeling. The man who has been accustomed to study natural objects philosophically, to be perpetually guarding against the delusions of the fancy, will not readily be induced to multiply words so as to forget things. From observing in the relations of inanimate things fitness and utility, he will reason with deeper reverence concerning beings possessing life; and perceiving in all the phenomena of the universe the designs of a perfect intelligence, he will be averse to the turbulence and passion of hasty innovations, and will uniformly appear as the friend of tranquillity and order.