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the chemical philosopher what grammars and dictionaries accomplish for the linguist. The difficulties of both pursuits soon vanish, and the original chaos is marshalled into a system of perfect simplicity and order.

Having thus endeavoured to explain and illustrate the abstract nature of chemistry, I shall next attempt to point out the practical applications of the science, its importance as a branch of general education, especially for the natives of this country, and above all, its essential, its vital necessity to the medical student.

As a department of the general student's education, the knowledge of the properties of these simple substances and their compounds, is fraught with manifold advantages; of these, one of the most valuable, is its peculiar tendency to the formation of habits of sober and philosophical reasoning. Its very essence being the discovery of the qualities which distinguish one material substance from another, it trains the student by an insensible but irresistible power in the discrimination of truth from error in all its relations whether metaphysical or material. It is, in fact, one of the best systems of practical logic a youth can learn. It teaches him how to observe and appreciate the minutest shades of difference as well as the widest generalization of facts, and it does this, not by an appeal to our mental faculties alone, not by the dry comparisons of the sides of triangles or diameters of spheres, but through the channels of all our perceptions by what we see and hear and feel and taste and smell. On the first occasion of my addressing the classes of the Medical College, I quoted in support of these opinions a passage from an essay by Mr. Parkes, which seems to me to bear so appropriately on the subject that I may perhaps be pardoned for referring to it again ; in alluding to the use of chemistry as a syllogistic system alone, Mr. Parkes emphatically says. “It may be remarked that it is the necessary consequence of this study that it gives the habit of investigation and lays the foundation of an ardent and enquiring mind. If a youth has been taught to receive nothing as true, but what is the result of experiment, he will be in little danger of being led away by the insidious arts of sophistry, or having his mind bewildered by fanaticism or superstition. The knowledge of facts is what he has been taught to esteem, and no reasoning, however specious, will ever induce him to receive as true what appears to be incongruous or cannot be recommended by demonstration or analogy.”

Such was the opinion of Mr. Parkes, one of the most elaborate and highly informed writers on this subject. But it is not merely on these moral grounds that I would seek to establish the importance of the study to the general native student, other and perhaps more persuasive reasons may be laid before him. By becoming proficient in this science, he learns the certain means of obtaining lucrative employment and considerable distinction. We are in India situated in the vicinity of many territories to which Europeans are denied access, and which a scientific eye has never yet explored. These are open to the ingress of our native fellow subjects, but they know not how to make the observations which chiefly render travels of scientific interest or utility. But if possessed of due knowledge of chemistry and natural philosophy, the native traveller would enter these unstudied regions and view them as he would a book in a familiar tongue. He could ascertain the heights of their mountains, the nature of their soils, the character and value of their mineral riches, the composition of their drugs and dye stuffs, and all this with an apparatus not worth one hundred rupees. But not to step beyond the limits of our own possessions, we might point to climates and localities where a European dare not venture, but where a native may reside with impunity, where rich mines of the precious metals, as well as of copper, iron, tin, and lead have been discovered, sources of inexhaustible national and individual wealth, but now utterly profitless through the extreme ignorance of the natives of the mode of working the ores. In illustration of what can be effected in this department, I may mention that in a series of specimens sent to me from a native copper mine in Kemaon, the mere slags (or the part considered as waste by the workmen) were richer in copper than many ores which are turned to great profit in the hands of educated men. Under such a system native mining must be indeed a very useless calling, while if prosecuted by persons trained in chemistry for a few months, it would become a fertile source of national and individual emolument. Analogous cases are so numerous that they would occupy a long lecture to detail them. Possessed of many of the finest dye stuffs in the world, India is forced to export them to a more enlightened land, where the cottons also exported from India receive their colors and return to the place of their original production. I might adduce the instance of the Turkey red and of the permanent shawl green in proof of what India loses by her ignorance of the chemistry of the arts. The Turkey red cottons are well known in the markets of Bengal for their fine and permanent color, and their high price, yet though all the materials used in the process are of Indian growth, the skill to apply them does not exist, and the consumer is consequently forced to pay the expenses of their exportation to Europe and their return to India, as well as the remuneration of the European dyer. It is an authenticated fact that the shawl weavers of Cashmere and upper India have on more than one occasion purchased up English green cloth at fifteen rupees a yard merely for the purpose of extracting the green dye with which it was colored. In the manufacture of porcelain, glass and various kinds of pottery, in the production of saltpetre, the cultivation of opium, the growth and purification of drugs and dye stuffs, for the wholesale market, the same wide field exists, in which numbers of young men would find lucrative employment, and would, moreover, be the source of inestimable benefit to their countrymen by disseminating among them the knowledge of the improved process by which the value of the manufactures alluded to would be enhanced beyond calculation.

Such are a few of the useful applications to which the general student may turn this captivating science. It is one, moreover, which the humblest mind can sufficiently comprehend and avail itself of, while to the highest and most gifted it affords unbounded scope for the employment of all its endowments. Duly impressed with the necessity of disseminating such valuable knowledge, our most patriotic and enlightened statesmen, and other individuals of high rank in England, have within the last few years lent all their influence to the establishment of Mechanics’ Institutes throughout the manufacturing towns ; in these institutions regular lectures on chemistry are delivered and crowds of humble citizens receive gratuitous instruction. The result is already known—from the ranks of the workman and the mechanic have sprung up a multitude of men of genius, whose endowments would otherwise have been thoroughly lost to mankind. Every art and manufacture has already felt the impetus of this mighty power of education ; inventions are daily patented and their practicability proved which but a few years since were merely talked of and laughed at as idle chimerical dreams. In short, the progress of improvements becomes so rapid and extraordinary, that it is difficult even to speculate on the limits which human ingenuity will ultimately find.

But even here I cannot close the enumeration of the motives which should influence the general student in the prosecution of this study. I am aware that among my native pupils there are many young men whose affluent circumstances will place them beyond the necessity of turning chemistry to purposes of emolument, and who perhaps may reasonably feel no ambition for distinction in this or any other science. But even to this section of native pupils I can hold forth inducements enough in the mental gratification every rational being must derive from the views this study communicates of the beauty, the simplicity, and the design which pervade all the natural phenomena around us. A

lecture I once attended at the Royal Institution of London, may well illustrate this position. The lecturer treated of the nature and properties of the air, of the atmosphere we breathe.

He took a portion of the air of the room in which the audience was assembled. He analysed it and shewed that in that invisible, impalpable sluid there were two disserent gases; these gases again he extricated from other substances, and imitating nature's own processes he made atmospheric air. By appropriate experiments he caused mists and clouds to form, and miniature lightning to play through the air he thus created. He caused iron to burn like tinder in one of its elements and by the combustion of lime produced a light as intolerable to the eye, as the rays of a noon-day sun. Water, he shewed congealed in a few moments as if by winter, he then separated its elements and made them re-unite with an explosion like the thunder, and such heat that flint and agate melted before it like wax before an ordinary fire; and to crown the demonstration, he lastly exhibited the same elements in another form, impelling a steam engine with the power of an elephant but obedient to the finger of a child. The audience on that occasion were composed of many distinguished noblemen, jurists, military officers, divines and other individuals of general education, and all seemed equally delighted with what they had witnessed. If then this science discloses such attractions, that it is followed with avidity by these distinguished classes of society, the native general student may with confidence become their imitator in this as in many other pursuits.

But if chemistry be thus profitable and gratifying to the general student, the medical student derives from it such inestimable benefit that I feel bound to point out in some detail the leading applications of the science to medicine and its tributary or dependent pursuits.

Though the nature of life is yet utterly unknown, and perhaps altogether inscrutable, we find that in the living body there are constantly taking place numerous chemical actions essential to life's continuation. Of these one of the most important, is respiration or breathing. Chemistry has long since pointed out that the air we breathe is not as the ancients thought, and as the uneducated still believe, an elementary or simple substance but composed of oxygen and nitrogen gases, with small quantities of an air called carbonic acid, and it has further proved the extraordinary fact that it is the oxygen alone which supports our breathing and thus maintains our lives. The nitrogen lends no assistance to the function; but most strange of all, the carbonic acid which exists in the air we are at this moment respiring, is a poison of such power that if it was present in the proportion of but one to four parts of air, every individual in this room would instantaneously perish. By various natural and artificial processes this poison is produced abundantly on the surface of the globe. In many places it accumulates rapidly to the imminent danger of those who approach incautiously. A moderate knowledge of chemistry, however, enables us not only to ascertain when its proportion becomes too great, but when this has happened to render it perfectly harmless. It leads us too, by our knowledge of the cause of the accident, to efficient means of treatment and cure. Many of the pupils now present recollect the experiment I showed them in demonstration of these facts, and how a bird apparently killed by carbonic acid, on the application of the proper treatment, instantaneously recovered and flew from the table,

The applications of chemistry to the study of respiration, and the understanding and treatment of many other accidents, and of some diseases in which our breathing is concerned, would in itself occupy more than one lecture, I shall consequently turn to other and equally important applications of the science in medical pursuits. In the digestion

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of our food, it has revealed the elements which most contribute to the nutriment of animals, explained many of the wonderful changes by which our food is converted into blood and slesh and bone identical with our own. It has taught us how to relieve many painful and dangerous diseases of the digestive organs by strictly chemical means, and it has shewn mankind how to extract wholesome, palatable and nutritious food from many substances long supposed to be utterly destitute of utility.

In diseases of the urinary organs again, in stone and gravel sor instance, a knowledge of chemistry is indispensable. The stones formed are of different kinds, in fact of opposite constitution. Some of them are dissolved or their formation prevented and the patients cured by means of remedies, which would to a certainty have the effect of aggravating the disease were the stone of a different chemical constitution. In short, if we understand chemistry, we can cure many cases of stone, and thereby spare our patients a dangerous and awful operation ; but if we are ignorant of that science, our remedies will in all probability make the disease infinitely worse than before.

Again, the blood and its secretions are only understood by the chemist, and he applies his knowledge of their composition to practical uses of the utmost importance; in some diseases, for example, the blood undergoes changes which chemistry alone can explain, and by this explanation we are guided in our research for appropriate systems of cure. Since the aera when medicine was first cultivated, no more remarkable event has occurred, no more extraordinary proof of the power of well directed science over disease has been exhibited than the one to which I am now about to call your attention. As soon as the pestilential cholera reached England, experiments were undertaken by the desire of the Central Board of Health, with a view to ascertain whether the blood or other fluids of the body underwent any change in the disease. I had the good fortune to have been employed for this purpose. Simple experiments, so simple that I have already taught many of this class how to perform them correctly, shewed that the blood was already in a remarkable degree—that it had lost a great quantity of the water it naturally contains, and the saline matter in which it also abounds. The inference seemed to me obvious, that whatever might be our ignorance of the cause of the disease, this at least was one of its essects which we should obviate before a cure could be accomplished. To effect this I proposed that at least in the desperate cases, abandoned by all other systems, an attempt should be made to restore the sluidity of the blood by injecting the substances it had lost directly into the veins. The suggestion was immediately adopted, and on the 10th of May, 1832, the first trial of the operation was made in Leith, by Dr. Latta of that place, and was attended with results perhaps the most wonderful of any recorded in the history of practical medicine. I quote Dr. Latta's words.

“The first subject of experiment was an aged female, on whom all the usual remedies had been fully tried without producing one good symptom. She had apparently reached the last moments of her earthly existence, and now nothing could injure her; indeed, so entirely was she reduced that I feared (Dr. Latta says) I should be unable to get my apparatus ready ere she expired. Having inserted a tube into the baslic vein cautiously, I anxiously watched the effects. Ounce after ounce was injected, but no visible change was produced; still persevering, I thought she began to breathe less laboriously ; now the sharpened features and sunken eye and fallen jaw, pale and cold, bearing the manifest impress of death's signet, began to glow with returning animation, the pulse which had long ceased returned to the wrist; at first small, weak, by degrees it became more and more distinct, fuller, slower, and firmer, and in the short space of half an hour, when six pints had been injected, she expressed in a firm voice that she was free from all uneasiness, actually became jocular, and fancied all she needed was a little sleep.”

Such were the immediate essects of the operation. It was immediately repeated on fifteen abandoned cases, cases of individuals apparently beyond all human relief. In every case the same respite was given, and five of these moribund dying patients completely recovered. Dr. Girdwood, of London, next came forward and out of seven cases obtained five perfect cures. In one of these, blood drawn from the patient one day before and three days after the operation, were given to me for chemical analysis. In the first, the blood was thirteen per cent. thicker than it naturally should be; in the second, after the operation, it had completely regained its natural density.

The instantaneous benefits invariably derived from this operation, and the number of cures obtained almost miraculously by its use, prove, at all events, the correctness of the principles on which it was founded. It is said to have failed in many cases. This is not surprising for many reasons; the patients on whom it has been performed hitherto have, in a vast majority of cases, been either dying or actually dead. We could not pretend to work miracles by this or any other method. But independently of this, the thoughtlessness or ignorance of many practitioners in performing the operation with common instead of distilled water, is quite sufficient to account for many of the reputed failures, and for this reason, common water invariably contains atmospheric acid. Now the injection of a minute portion of air into the veins is so rapidly fatal that this is the mode now adopted for killing horses at the tanneries of Paris.”

I might dwell at great length on this as on many other causes of the reported failure of this operation did my time permit, I now content myself with quoting from the most

eminent medical periodical of that day, its Editor's observations on one of these extraordinary cases.

“The case thus alluded to, we think, is one of the most interesting recorded in the annals of our profession. It entitles us to presume that as organic chemistry improves, as our knowledge of the relation between the blood and remedies of different kinds increases, the art of treating diseases in general will be placed on a more certain and rational foundation. It teaches us how boldly we may proceed when certain and scientific data are before us, and it thus dispells the all but cowardly timidity which has hitherto prevented the principles of the treatment in question from being carried into effect.”

These remarks are from a leading article in the Lancet Vol. 1. 1832, where full official reports will be found on all the particulars of this interesting subject.

I feel that I have now trifled so long with your patience that I must pass over very

briefly some other departments of medicine, in which chemistry is equally essential and valuable.

Among the foremost of these, especially in this country, is the study of the chemical composition of the medicines used in surgical and medical practice.

Some of the most powerful medicines we possess, such as calomel and the other compounds of mercury, lead, antimony, copper, iron, &c. are exclusively artificial preparations, all easily and cheaply and well made by those who understand chemistry, but only obtainable at enormous expense by persons uninformed in that science. In every bazar

* I may add too, that distilled water as it is commonly prepared, contains a considerable quantity of air also. For this important operation the water should be distilled so that air could not come in contact with it, and heated when required to the

due temperature in the receiving bottles, instead of using the rude mixture of hot and cold water generally employed.—Note by the Lecturer.

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