Chapter VI · LIFE OF DAVY. 1778 to 1829. (continued 2)

Davy gave the lecture on Radiant Matter on February 29. He said, ‘With respect to radiant or ethereal substances all our knowledge of it is obtained from the effect it produces on us and terrestrial bodies when in motion.

‘In our consideration of this subject it will be essentially necessary that we distinguish between knowledge and speculation. These terms in their meaning are palpably different, but yet have been intermixed and combined together in a very singular manner. The French chemists in particular speak of the materiality of heat, and of the nature of the compounds it forms, as confidently and as fluently as if they had undeniably proved it to be a body. They have blended their knowledge with speculation, and formed a theory that is very possibly untrue. The most eminent phenomena of radiation are to be observed in light.’

And then he passed on to the laws of light and dwelt on Herschel’s discovery that the heating power of red rays was to the green as fifty-five to sixteen, and that he had himself found the thermometer rose still higher beyond the red, and that heating rays are less refrangible than light rays; then he showed a wire heated by the voltaic battery in air and in vacuo, and said that he had proved ‘that the radiating power is three times as strong in an exhausted receiver as in the open air,’ and, ‘fully proves that radiation is not caused by undulations in the atmosphere. It is strongest when no atmosphere is present.’ He ends his account of the effects of radiant heat thus: ‘Were it not for this terrestrial radiation of earthly bodies, the heat would accumulate from the rays of the sun until at last the whole world would be uninhabitable.

‘But, besides the effects produced by the two species of radiant matter—radiant light and radiant heat—there are other effects—chemical effects—that take place caused by the action of some radiant matter that comes to us from the sun, perhaps a single substance that, independent of light and heat, causes effects by its own power.’ And then he showed an experiment of chlorine and hydrogen exposed to light.

He says, ‘There is a very singular analogy that exists between the rays at the violet end of the spectrum, hydrogen gas, and the negative pole of the voltaic battery; and opposed to it stands the analogy of the rays at the red end of the spectrum to positive electricity; they produce opposite effects to the first-mentioned arrangement, but act similar to each other.

‘If that sublime idea of the ancients that there is only one species of matter in the universe, and that its different properties depend on the difference of size, shape and other qualities should be confirmed, it would simplify the science in a most eminent degree, and at the same time it would raise it to the acme of perfection.’

Opposing the view that oxygen gas contained light combined with it, and gave light out in oxidation, he contrasted slowly oxidised iron with an iron turning burnt in oxygen.

‘When the laws which govern in chemical science are fully known, there is no doubt it will become a much more simple science. It cannot fail to be so, since then it will be complete. Already it is one of the most useful of the whole circle to man, and when in its utmost state of improvement it will be one of the most sublime. It will, I have no doubt, connect mechanical and chemical sciences together; it will concentrate them into one and in that one comprehend the whole universe.

‘The first step to truth is the confession of ignorance. No man could have made the immortal discoveries of Newton unless he had first thrown up the ridiculous doctrines of Des Cartes. To attend to our errors and own them, to sacrifice all selfishness to the science, not to support errors for the sake of vanity, ought to be the leading precepts of a philosopher. He should turn his endeavour to the advancement of science and not to the increase of his reputation. Let him fix steps for others to rise on, and he does more real good to science than if he had spent years in controversy on an equivocal point. Let him turn his thoughts to general views and try to contain the whole science in his grasp; he will then be calculated to arrange it, improve it, and reform it and place it in that order which tends so materially to its advancement.’

His lecture on Chlorine was given on Saturday, March 14; the previous week he had given a lecture on Oxygen, which was not reported by Faraday.

‘I will demonstrate what I affirm in a positive and satisfactory manner.

‘Accustomed for years to consider the chemical principles of the French School of Physical Sciences as correct, I had adopted them and put faith in them until they became prejudices, and I even felt unwilling to give them up when my judgment was fully convinced by experiment that they were erroneous. I know that this is the case in some degree with almost every person; he is unwilling to believe that he is wrong, and therefore feels averse to adopt what is right when it opposes his principles.

‘Pelletier died from inhaling this gas (chlorine). It supports combustion of a taper [experiment]; it does not contain oxygen.’ He showed by experiment that pure dry chlorine and hydrogen, when exploded, caused no moisture; no water was formed. This was the synthetical proof. Decomposition of muriatic acid gas by potassium was shown as the analytical proof. Compounds with phosphorus, ammonia, and sulphur all free from oxygen. ‘Oxygen does combine with chlorine. I have ventured to name the compound euchlorine; it is of a very bright yellow green colour. Names should represent things, not opinions, for in the last case they often tend to misrepresent and mislead.

‘As chlorine contained no oxygen, it became an inquiry well worth investigation to ascertain the part which chlorine acted in bleaching. It decomposes water and forms hydrochloric acid.’

‘Had Mr. Berthollet obtained oxygen from chlorine there would have been no error in his theory, but by not attending to the minute circumstances of his experiment, by not ascertaining that the water present acted no part and was not decomposed, he fell into an error, and of course all the conclusions he drew were false and erroneous. Nothing should be allowed but what can be proved by experiment, and nothing should be taken for granted upon analogy or supposition.’

Faraday concludes this lecture thus: ‘Mr. Davy now proceeded to comment and make observations on the former theory of chlorine gas. Here I was unable to follow him. The plan which I pursue in taking of notes is convenient and sufficient with respect to the theoretical and also the practical part of the lecture, but for the embellishments and ornaments of it it will not answer. Mr. Davy’s language at those times is so superior (and indeed throughout the whole course of the lecture) that then I am infinitely below him and am incapable of following him even in an humble style. Therefore I shall not attempt it; it will be sufficient to give a kind of contents of it.

‘He said that hypotheses should not be considered as facts and built upon accordingly. Nevertheless, if cautiously pursued, they might lead to mature fruit. That nothing should be taken for granted unless proved. By considering oxygen as contained in chlorine the whole chemical world had been wrapped in error respecting that body for more than one-third of a century.

‘He noticed that all the truly great scientific men were possessed of great humility and diffidence of their own opinions and powers. He spoke of Scheele, the discoverer of chlorine; observed that he possessed a truly philosophical spirit, gave up his opinions when he supposed them to be erroneous, and without hesitation or reluctance adopted those of others which he considered more correct; admired his spirit and recommended it to all philosophers; compared it to corn, which looked but simple and insignificant in blossom and asked for little praise, yet was the support of man.’

In this lecture Faraday gives the details of twenty experiments.

On April 8 Professor Davy lectured on Simple Inflammable Bodies. ‘Their number, excepting the metals, is six, which unite with oxygen and chlorine, the subjects of the two last lectures.’ He showed a jet of oxygen burning in hydrogen, and said, ‘In the burning of tallow, wax, oil, and wood it is the hydrogen of their bodies that causes the flame; though in most cases it is also combined with carbon, yet it is the hydrogen that produces the flame....

‘I have here a bladder filled with nitrous oxide gas; I will breathe it once or twice, but not so far as to incapacitate me from continuing the lecture. It produces a very pleasing sensation (far superior to the most exquisite liquors, such as champagne), and I have no doubt that if I were to continue it a few minutes longer I should make a very interesting exhibition to the company; but I would rather be excused....

‘If we suppose that the diamond is pure carbon, and is therefore the same as charcoal, we have a very strong presumptive reason to suppose that all matter is alike in all substances. If substances so opposite and so different as charcoal and diamond are in reality the same kind of matter, then the difference in other bodies is no proof that they also are not of the same kind of matter; and this would lead us to suppose that there is but one matter in nature, and that the difference in different bodies is owing to variety in the distance of the particles, to shape, and to size....

‘In conclusion several of these six simple combustibles I suspect to be compounds, and perhaps their nature may shortly be discovered....

‘What gives a strong colour to the idea of the compound nature of nitrogen is the quantity of it that can be obtained from animal bodies, whereas they imbibe none, they combine with none.

‘Sulphur and phosphorus both appear to be compound bodies when they are subjected to the power of a voltaic battery. A great quantity of hydrogen gas is evolved, so that it appears hydrogen is one of their constituent parts....

‘Whether these bodies are compound or not, they are objects of new research; they present new fields for the great, the industrious, the scientific, and the penetrating mind. Our horizon extends the higher we rise. The result of future inquiries will probably lay a foundation on which future ages and future generations may erect an edifice that will reach from earth to heaven.’

In this lecture Faraday noted twenty-two experiments.

The next day, April 9, Davy was knighted by the Prince Regent.

On April 10 Sir Humphry Davy gave his last lecture at the Royal Institution; it was on the Metals.

‘All the volatile metals burn with flame, and all those that are not volatile with sparks....

‘These, with the metals of the alkalies and the alkaline earths which I have had the good fortune to discover, make up the number to about forty.’

He shewed the mode of obtaining alkaline metals by voltaic decomposition; and earths by potassium.

The mode of obtaining the alkaline metals by chemical action alone was shown, but the experiment was not made. A quantity of potassium from common potash by iron was on the table.

‘The combustion of metals is according to their electricity, those containing the most electricity burning with the most energy. All those metals that are positive to others are also more inflammable than those others, and burn more readily....

‘That the metals of the earths and alkalies cannot exist at the surface of our globe we are well assured, but they may exist in the interior, and if so they will offer a very complete and a very probable solution of the phenomena of earthquakes and volcanoes; and perhaps, considered thus, they may lay the foundation of a new and perfect system of geology.

‘We have here a small volcano formed of clay, &c., in the shape of a mountain, and having two or three pieces of the alkaline metals introduced here and there. Now by adding a little water to this volcano I shall be able to inflame it and cause it to burn briskly....

‘Meteors consist of alkaline metals and iron; the iron burns last if it be burnt at all.

‘What I conceive is, that there are certain bodies that revolve round our earth—a kind of satellites—and are the same with respect to our globe that comets are to the sun. Their orbits are ellipses, whose longer diameters, like those of the comets, far exceed their shorter ones. They must move with very great velocity to counteract the attraction of the earth....’

Regarding transmutation of metals he said ‘the beginning was deceit, the progress falsehood, and the end beggary, said Lemery.’

‘It was supposed till lately that the fixed alkalies were simple bodies, but I have had the good fortune to prove them compounds; and that pure potash should contain a metal, oxygen, and water is not more probable than that the metals are compounds, yet it not only is probable but it is possible, and in reality is so....

‘From the mercurial amalgam and from the quantity of hydrogen given out by metals when exposed to the action of a vigorous voltaic battery, either this hydrogen is combined with the metal or it is one of its constituent parts....

‘If, then, we suppose that hydrogen constitutes a part of all metals, they will be compounds of it and a base. The hydrogen will give them their genuine characters and make them metals, and their base will bestow on them their own peculiar properties.

‘I should wish particularly on this point to be understood rightly. I am not an advocate for alchemy and its attendant frauds; that will appear from the tenor of my discourse; but I conceive it to be a noble and glorious object to follow up the paths trod by those chemists who wish for the improvement of science to ascertain the compound nature of metals. It is a subject well worthy of pursuit, and whenever the discovery is made it will confer immortal honour on the discoverer, the age, and the country that it is made in.’

Faraday then says, ‘Having thus given the general character of the metals, Sir H. Davy proceeded to make a few observations on the connection of science with the other parts of polished and social life. Here it would be improper for me to follow him. I should merely injure and destroy the beautiful, the sublime observations that fell from his lips. He spoke in the most energetic and luminous manner of the advancement of the arts and sciences, of the connection that had always existed between them and other parts of a nation’s economy. He noticed the peculiar congeries of great men in all departments of life that generally appeared together, noticed Anaximander, Anaximenes, Socrates, Newton, Bacon, Elizabeth, &c., but, by an unaccountable omission, forgot himself, though I will venture to say no one else present did.

‘During the whole of these observations his delivery was easy, his diction elegant, his tone good, and his sentiments sublime.’

Faraday ends his volume with the notes of eighteen experiments that were made in this lecture.

The same day Davy wrote to his brother. It was the eve of his wedding.

Friday, April 10, 1812.

My dear Brother,—You will have excused me for not writing to you on subjects of science. I have been absorbed by arrangements on which the happiness of my future life depends. Before you receive this these arrangements will, I trust, be settled, and in a few weeks I shall be able to return to my habits of study and scientific research. I am going to be married to-morrow, and I have a fair prospect of happiness with the most amiable and intellectual woman I have ever known.

The Prince Regent, unsolicited by me or by any of my intimate friends, was pleased to confer the honour of knighthood on me at the last levée. This distinction has not often been bestowed on scientific men, but I am proud of it, as the greatest of human geniuses bore it; and it is at least a proof that the world has not overlooked my humble efforts in the cause of science.

I am, my dear Brother, most affectionately yours,

H. Davy.

On June 12 he published his ‘Elements of Chemical Philosophy.’ It is dedicated to Lady Davy, ‘as a pledge that he shall continue to pursue science with unabated ardour.’

Dr. Thomas Young, in the ‘Quarterly Review’ for September 1812, enables us to see what was thought of Sir H. Davy and of his book at this time.

‘In attempting a review of this work we cannot avoid professing that we are far from entertaining the impression of sitting down as competent judges to decide upon the merits or demerits of the author; on this point the public voice, not only within our own islands, but wherever science is cultivated, has already pronounced too definite a sentence to be weakened or confirmed by anything that we can suggest of exception or approbation. Our humble labours on such an occasion must be much more analytical and historical than critical; at the same time we are too well acquainted with the author’s candour to suppress any remark which may occur to us as tending to correction or improvement. It has most assuredly fallen to the lot of no one individual to contribute to the progress of chemical knowledge by discoveries so numerous and important as those which have been made by Sir Humphry Davy; and, with regard to mere experimental investigation, we do not hesitate to rank his researches as more splendidly successful than any which have ever before illustrated the physical sciences in any of their departments. We are aware that the “Optics” of Newton will immediately occur to our readers as an exception; but, without attempting to convince those who may differ from us on this point, we are disposed to abide by the opinion that for a series of well-devised experiments and brilliant discoveries the contents of Davy’s “Bakerian Lectures” are as much superior to those of Newton’s “Optics” as the “Principia” are to those or to any other human work for the accurate and refined application of a sublime and simple theory to the most intricate and apparently anomalous results derived from previous observation.

‘Until the year 1806 Sir Humphry Davy had been remarkable for the industrious and ingenious application of those means of experiment only which had been long known to chemists. He had acquired at a very early period of his life a well-established celebrity among men of science throughout Europe by the originality and accuracy of his researches, and at the same time the fluent and impressive delivery of his lectures had obtained him the most flattering marks of approbation from the public of the metropolis. But it was in the summer of that year that, in repeating some electro-chemical experiments of very doubtful authority (the production of acid and alkali by the decomposition of water), he was led into a new train of reasoning and investigation, which enabled him to demonstrate the important laws of the connection between the electrical affections of bodies and their chemical powers. This was his first great discovery.... Our author’s next great step was the decomposition of the alkalies, which he effected the succeeding year; and this, though less interesting and important with regard to the fundamental theory of the science, was more brilliant and imposing from its capability of being exhibited in a visible, tangible form. The third striking feature which distinguishes the system advanced in the present work is the assertion of the existence of at least two empyreal principles—oxygen and the elastic fluid called the oxymuriatic acid gas (chlorine)....

‘A fourth peculiarity, which, however, is less exclusively and originally a doctrine of Sir Humphry Davy, is the theory of the simplicity of the proportions in which all bodies combine—a theory the explicit illustration and general and minute application of which the science is principally indebted to our countryman Mr. Dalton.’

How far later discoveries have advanced our knowledge can be seen in the strange words, as they now sound, which Dr. Young uses when he mentions the first researches of Davy.

‘Certain bodies which attract each other chemically, and combine when their particles have freedom of motion, when brought into contact still preserving their aggregation, exhibit what may be called electrical polarities, and by certain combinations these polarities may be highly exalted; and in this case they become subservient to chemical decompositions, and, by means of chemical arrangements, the constituent parts of bodies are separated in uniform order and in definite proportions.’

The review then gives the account of the discovery of potassium, sodium, barium, strontium, magnesium, aluminum, glycinium, zirconium, silicium, and itrium and boron.

On the subject of oxymuriatic acid gas Dr. Young says ‘we cannot help thinking his tone somewhat more decisive than the present state of the investigation altogether authorises,’ and he strongly objects to Davy’s terminology; which never was adopted by chemists.

As no table of the proportional weights of chemical substances entering into combination is to be found in Sir H. Davy’s work, Dr. Young says he took the liberty of inserting one formed from Davy’s numbers and from the experiments of Berzelius and Richter.

He thus ended his review, ‘The character of Sir Humphry Davy’s researches has always been that of the most interesting originality, and we have certainly no reason to complain that he has in his experiments very commonly forsaken the beaten path.

‘With all its excellences this work must be allowed to bear no inconsiderable marks of haste, and we would easily have conjectured, even if the author had not expressly told us so in his dedication, that the period employed on it “has been the happiest of his life.” In that and in every other happiness which may have befallen him we shall ever most sincerely rejoice; nor shall we think the public will have any reason to reproach him with having done too little for science, even if he should fail at any future time in his avowed resolution of pursuing it “with unabated ardour;” that he has not yet so failed is become from a late accident a matter of public notoriety, and if we may expect perseverance to be at all commensurate to success, we have no reason to be apprehensive of his passing any part of his life in inactivity.

‘The style and manner of this work are nearly the same with those of the author’s lectures delivered in the theatre of the Royal Institution. They have been much admired by some of the most competent judges of good language and good taste, and it has been remarked that Davy was born a poet, and has only become a chemist by accident. Certainly the situation in which he was placed induced him to cultivate an ornamented and popular style of expression and embellishment, and what was encouraged by temporary motives has become natural to him from habit. Hence have arisen a multitude of sentimental reflections and appeals to the feelings, which many will think beauties and some only prettinesses; nor is it necessary for us to decide in which of the two classes of readers we wish ourselves to be arranged, conceiving that in matters so indifferent to the immediate object of the work a great latitude may be allowed to the diversity of taste and opinion.’

On June 18 Davy sent a paper to the Royal Society on ‘Some Combinations of Phosphorus and Sulphur,’ and in July two other papers—‘Further Observations on Chloride of Nitrogen; and on Fluorine and Hydrofluoric Acid.’

Late in August he wrote to a friend, ‘I have just published a volume of the ‘Elements of Chemistry,’ and I hope to publish another in the course of the spring. Having given up lecturing, I shall be able to devote my whole time to the pursuit of discovery.’

On October 14, from Edinburgh, he wrote to Mr. Children:

‘I have received a very interesting letter from Ampère. He says that a combination of chlorine and azote has been discovered at Paris, which is a fluid and explodes by the heat of the hand, the discovery of which cost an eye and a finger to the author. He gives no details as to the mode of combining them. I have tried in my little apparatus with ammonia cooled very low and chlorine, but without success.’

On October 24 he writes, ‘On Wednesday we are to have a meeting at the Institution, to try to make this compound of azote and chlorine.’

On November 5 a letter was read at the Royal Society from Davy to Sir Joseph Banks on this compound, which had been formed by exposing chlorine to a solution of nitrate of ammonia. During his investigation the substance exploded in a tube, and he received a severe wound in the eye.

On November 16 he wrote to his brother, ‘It is not safe to experiment upon a globule larger than a pin’s head. I have been severely wounded by a piece scarcely bigger.’

In January 1813 he had another severe attack of inflammation in the wounded eye, and it was not perfectly well till April.

On April 4 he wrote to his brother, ‘I am now quite recovered, and Jane is very well, and we have both enjoyed the last month in London. I have been hard at work (on fluorine). We have now a triad of supporters of combustion.

‘I have just finished printing my “Agricultural Lectures.”’

Soon after he again wrote to his brother:

I communicated to you in a former letter my plans as far as they were matured. I have neither given up the Institution nor am I going to France, and, wherever I am, I shall continue to labour in the cause of science with a zeal not diminished by increase of happiness and (with respect to the world) increased independence.

I have just finished the first part of my ‘Chemistry’ to my own satisfaction, and I am going to publish my ‘Agricultural Lectures,’ for which I am to get 1,000 guineas for the copyright and fifty guineas for each edition, which seems a fair price. As I shall see you so soon I shall not write about any matters of science.

I was appointed professor (honorary) to the Institution at the last meeting (April 5). I do not pledge myself to give lectures. Brande gives twelve.

If I lecture it will be on some new series of discoveries, should it be my fortune to make them, and I give up the routine of lecturing merely that I may have more time to pursue original inquiries and forward more the great objects of science. This has been for some time my intention, and it has been hastened by my marriage.

I shall have great pleasure in making you acquainted with Lady D. She is a noble creature (if I may be permitted so to speak of a wife) and every day adds to my contentment by the powers of her understanding and her amiable and delightful tones of feeling. God bless you!

Believe me to be your affectionate brother, H. Davy.

In the minutes of the monthly meetings of members of the Royal Institution, April 5, 1813, it is stated that Sir H. Davy rose and begged leave to resign his situation of Professor of Chemistry; ‘but he by no means wished to give up his connection with the Royal Institution, as he should ever be happy to communicate his researches in the first instance to the Institution in the way he did in the presence of the members last Wednesday (on hydrofluoric acid), and to do all in his power to promote the interest and success of this Institution.’

Earl Spencer moved ‘that the thanks of this meeting be returned to Sir H. Davy for the inestimable services rendered by him to the Royal Institution, and that, in order more strongly to mark the high sense entertained by this meeting of the merits of Sir H. Davy, he be elected Honorary Professor of Chemistry.’

Mr. Brande was then nominated Professor of Chemistry, with a salary of 200l. per annum.

In October Sir H. Davy went abroad with Mr. Faraday.

In May 1815 he came back, and Faraday was re-engaged as the assistant in the laboratory of the Royal Institution. Whilst abroad he had sent as many as seven papers to the Royal Society—on ‘Fluoric Acid Compounds and Hydrogen Acids.’ Two papers on ‘Iodine,’ on ‘Combustion of the Diamond,’ on ‘Ancient Colours,’ on a ‘Solid Compound of Iodine and Oxygen,’ on ‘Hyperoxy-Muriates.’

When he returned he probably intended to make greater discoveries in chemistry during the following ten years than he had made during the fifteen years that he had been at the Institution. He was in the prime of life. He had won the highest rank as an original inquirer. He had a love of research which, in spite of his marriage, his wealth, and ultimately his ill health, never ceased until his early death. He had Faraday as his assistant, and he soon found a subject more fruitful than the composition of nitrogen, which had so long baffled his genius.

Many of the details of his work in the laboratory until his last experiment on the diffusion of gases, in February 1826, are to be found in the ‘Life of Faraday.’ It will be sufficient to give here a statement of the original researches which he communicated to the Royal Society.

In November 1815 and January 1816 his papers on Fire-damp were read. He then worked upon flame, and in January 1817 his researches on flame and his splendid invention of the Davy Lamp were laid before the Royal Society. At this time the popular reputation of Davy reached its climax, and, looking back, we can now see that his life should have ended here; he was then only 38 years old. He was presented with a service of plate as a token of his invaluable invention by the coal owners of the Tyne and Wear. He bequeathed this to the Royal Society for the foundation of a medal, to be given yearly to the chemist who made the greatest discovery. This prize should be looked on as a lasting memorial of the countless lives which Davy and other chemists, by the application of their scientific researches, have preserved.

Year after year, from 1817 to 1826, Davy communicated new investigations to the Royal Society. He worked on chlorine, on phosphorus, on mists. He went abroad again, and he tried chemically to unfold the Herculanean papyri. He returned in 1820, and was elected President of the Royal Society after the death of Sir Joseph Banks. Then he worked on magnetic phenomena produced by electricity, on electric phenomena in vacuo, on water in the cavities of crystals, on new phenomena of electro-magnetism. He became jealous of the discoveries of Faraday, and he sent a paper to the Royal Society on the ‘Application of Liquids Formed by the Condensation of Gases as Mechanical Agents.’

In 1823 he began to work on the defence of the copper sheathing of ships, and in 1824 he had two papers published on this subject. He went in a Government steamboat to Norway, Sweden, and Denmark for the purpose of trying the influence of motion on his protectors. He had already suffered for a year at this time from ill health. In 1825 his paper on the ‘Preservation of Metals by Electrochemistry’ was published. In practice his plan failed, and he was too ill to bear lightly the disappointment of his expectations. In 1826 he had a paper read on the ‘Relations of Electrical and Chemical Changes.’ It contained but little new matter. On November 30 he was elected President of the Royal Society for the last time. He was dangerously ill on the day of election.

In the middle of December 1826 he was struck with paralysis of the right side.

With the restlessness of disease on January 22, about a month after his attack, he set out for Italy. He had the worst possible journey across Mont Cenis, and, after being three weeks at Ravenna, in the middle of March he wrote to Mr. Poole:

I am, thank God, better, but still very weak and wholly unfit for any kind of business and study. I have, however, considerably recovered the use of all the limbs that were affected, and, as my amendment has been slow and gradual, I hope in time it may be complete. But I am leading the life of an anchorite, obliged to abstain from flesh, wine, business, study, experiments, and all things that I love; but this discipline is salutary, and, for the sake of being able to do something more for science, and I hope for humanity, I submit to it, believing that the Great Source of intellectual being so wills it for good.

One of the last thoughts in his note-book, written at Ravenna, shows his mind:

‘Our real knowledge is but to be sure that we know nothing, and I can but doubt if this be a curse or blessing. Those who hope, trust, and believe are surely happier far than those who doubt; and the submissive child, who of his father’s goodness is secure, is far more blessed than the froward one, who sets himself against his powerful will, which, after all his struggles and vain efforts, he must at last obey, rebelling against the love which would have made him happy. Is not this the history of man?—of that bright and beauteous garden where in innocence and ignorance he lived and loved till the false taste of knowledge made him wretched and he knew that he must die. And is not this the glory and the consummation of the Christian faith, which gives him back his innocence, his hopes, his confidence in God, which through his life still gilds the future with a golden blessing of an expected immortality? Man fell in Adam; knowledge was his bane; man rose in Christ, recovering his ignorance or substituting hope for what was doubt.’

Four or five days before he left Ravenna he wrote, April 6, ‘Did not shoot, but returned thanks to the Great Cause of all being for all His mercies to me, an undeserving and often ungrateful creature, but now most grateful. May I become better and more grateful and more humble-minded every day!’

‘Valde miserabilis’ is not an unfrequent expression at this time, commonly accompanied with mention of diminished power of limbs and general feebleness, with pain and numbness. Sometimes he was in despair of recovery and resigned to his fate, at other times indulging in hope, thankful for feeling better, and expressing thanks (and he does it very often) by the use of letters; as G. G. D. (Thanks and glory to God); O. O. O.; or more fully thus, G. O. O. O. D.

On July 1 he wrote to his friend Mr. Davies Gilbert, who was on the council of the Royal Society. He says that the expectations of his complete and rapid recovery have not been realised.

Under these circumstances I feel it would be highly imprudent, and perhaps fatal, for me to return and to attempt to perform the official duties of President of the Royal Society; and as I had no other feeling for that high and honourable situation except the hope of being useful to the society, so I would not keep it a moment without the security of being able to devote myself to the labour and attention it demands. I beg, therefore, you will be so good as to communicate my resignation to the council and to the Society at their first meeting in November, stating the circumstances of my severe and long-continued illness as the cause. At the same time I beg you will express to them how grateful I feel for the high honour they have done me in placing me in the chair for so many successive years. Assure them that I shall always take the same interest in the progress of the grand objects of the Society, and throughout the whole of my life endeavour to contribute to their advancement and to the prosperity of the body.

He continued his notes thus:

‘September 2.—I took my exercise well with less fatigue, and certainly feel better. Offered up my thanksgiving to the O. O. O. with tears of gratitude and feelings of intense adoration,

‘September 27, St. Goar.—A very beautiful and glorious evening. I thought I was going to be quite well, as the weakness of the left wrist, which put an end to my shooting at Spiers, is quite gone; but I found my stiff leg as bad as ever. Yet I can hardly be lower or live lower. Dubito fortissime restaurationem meam.

‘As I have so often alluded to the possibility of my dying suddenly, I think it right to mention that I am too intense a believer in the Supreme Intelligence, and have too strong a faith in the optimism of the system of the universe, ever to accelerate my dissolution. The laurel-water and laudanum and opium that are in my dressing-case are medicines. I have been and am taking a care of my health which I fear it is not worth, but which, hoping it may please Providence to preserve me for wise purposes, I think my duty. G. O. O. O.’

He arrived in London on October 6. Not finding his health improve, on March 29, 1828, he left England again. Before he went he sent a paper on Volcanoes to the Royal Society.

In his ‘Consolations in Travel’ he says, ‘I was desirous of again passing some time in Southern Austria and Italy, in the hope of re-establishing a broken constitution, and though this hope was a feeble one, yet at least I expected to spend a few of the last days of life more tranquilly and more agreeably than in the metropolis of my own country. Nature never deceives us. The rocks, the mountains, the streams, always speak the same language. A shower of snow may hide the verdant woods in spring, a thunder-storm may render the blue, limpid streams foul and turbulent; but these effects are rare and transient; in a few hours, or at least days, all the sources of beauty are renovated; and Nature affords no continued trains of misfortunes and miseries, such as depend upon the constitution of humanity, no hopes for ever blighted in the bud, no beings full of life, beauty, and promise taken from us in the prime of youth. Her fruits are all balmy, bright, and sweet; she affords none of those blighted ones so common in the life of man and so like the fabled apples of the Dead Sea, fresh and beautiful to the sight, but when tasted full of bitterness and ashes.’

On May 22 he writes, ‘To my old haunt, Wurzen, which is sublime in the majesty of Alpine grandeur. The snowy peaks of the Noric Alps rising above thunder-clouds, whilst spring in all its bloom and beauty blooms below, its buds and blossoms adorning the face of nature under a frowning canopy of dark clouds, like some Judith beauty of Italy—a Transteverene brow and eye and a mouth of Venus and the Graces.’

On June 3 he wrote to his brother, Dr. Davy:

Aussee, in Styria.

Notwithstanding the long, severe, and depressing malady under which I still labour I am not entirely without hope of ultimate recovery, and the few pleasures which I retain in this my state of earthly purgatory have principally reference to the enjoyments and prospects of my friends; and I indulge in the idea that you are well and happy and enjoying a life which I can say I only support, supposing that it pleases Omniscience to preserve me for some ends which I cannot understand, but which I trust belong to the great plan of goodness and mercy belonging to the Divine mind.

It suits me better to write away my days in this solitary state of existence in the contemplation of nature than to attempt to enter into London society, where recollections call up the idea of what I was, and the want of bodily power teaches me what a shadow I am. I make notes in natural history, fish, and prepare for another edition of my ‘Salmonia;’ ride amongst the lakes and mountains; and attach the loose fringe of hope as much as possible to my tattered garments. I am now going to Ischel, where there are warm salt baths, to try if they will renovate the muscular power of my leg and arm.

I wish to go to Trieste in October, to make the experiments I have long projected on the torpedo. God bless you, my dear John!

Your affectionate Friend and Brother, H. Davy.

On June 24 he says:

I have used the baths. I have nearly recovered the flexibility of the affected limbs, but not their former strength, and this I can hardly hope to do as long as I am obliged to live so low and to use so much medicine; but I shall go on. Speranza!

In November he sent his last paper to the Royal Society. It was on the Torpedo.

On December 21 he wrote to his brother:

Rome.

Perhaps in the spring you could see me in Illyria. I would then show you my kind little nurse, to whom I owe most of the little happiness I have enjoyed since my illness.

He had stopped his treatment for four months and had lived rather more freely, but in ‘every respect I have continued extremely temperate.’

On January 30, 1829, he was still at Rome. He said, ‘The palpitation of the heart has increased almost alarmingly, and I do not think I have gained any strength in the weak limbs.’

On February 1 he wrote in his journal, ‘Finished the dialogues fifth and sixth’ (these ended the ‘Consolations in Travel’). ‘Si moro, spero che ho fatto il mio dovere, e che la mia vita non e stata vana ed inutile.’

On February 6 he wrote to his friend Poole from Rome:

Would I were better, I would then write to you an agreeable letter from this curious city; but I am here wearing away the winter, a ruin amongst ruins.

I write and philosophise a good deal, and have nearly finished a work with a higher aim than the little ‘Salmonia,’ which I shall dedicate to you. It contains the essence of my philosophical opinions and some of my poetical reveries. I sometimes think of the lines of Waller:

I have, notwithstanding my infirmities, attended to scientific objects whenever it was in my power, and I have sent to the Royal Society a paper, which they will publish, on the ‘Peculiar Electricity of the Torpedo,’ which I think bears remotely on the functions of life. I attend a good deal to natural history.

I fight against sickness and fate, believing I have still duties to perform, and that even my illness is connected in some way with my being made useful to my fellow-creatures. I have this conviction full on my mind, that intellectual beings spring from the same breath of Infinite Intelligence, and return to it again, but by different courses, like rivers born amidst the clouds of heaven and lost in the deep and eternal ocean; some in youth rapid and short-lived torrents, some in manhood powerful and copious rivers, and some in age by a winding and slow course, half lost in their career and making their exit by many sandy and shallow mouths. [And then he asks him if he will come and travel with him.] But I write as if I were a strong man, when I am like a pendulum, as it were, swinging between death and life. God bless you, my dear Poole!

Your grateful and affectionate Friend, H. Davy.

A fortnight afterwards he had another severe attack of paralysis of the right side.

On February 23, three days after the attack, he dictated a letter to his brother.

My dear John,—Notwithstanding all my care and discipline and ascetic living I am dying from a severe attack of palsy, which has seized the whole of the body with the exception of the intellectual organ. I am under the usual severe discipline of bleeding and blistering, but the weakness increases, and a few hours or days will finish my mortal existence. I shall leave my bones in the Eternal City. I bless God that I have been able to finish all my philosophical labours....

God bless you, my dear brother! may you be happy and prosperous!

Your affectionate Friend and Brother, H. Davy.

The 25th he dictated another letter, chiefly on the torpedo; it ends:

Pray do not neglect this subject, which I leave to you as another legacy. God bless you, my dear brother!

Your affectionate Friend, H. Davy.

He tried to write a postscript, and he did write ‘My dear John;’ then he dictated, ‘I am dying; come as quickly as you can. You will not see me alive, I am afraid. God bless you!’

On March 16 Dr. Davy reached him. ‘Never shall I forget,’ he says, ‘the manner in which he received me, the joy which lighted up his pale and emaciated countenance, his cheerful words and extreme kindness, and his endeavours to soothe a grief which I had not the power of controlling on finding him so ill, or rather at hearing him speak as if he were a dying man, who had only a few hours to live, and who wished to use every moment of such precious time. With a most cheerful voice, a smile on his countenance, and most warm pressure of the hand, he bade me not be grieved, but consider the event as a philosopher. He expressed his pleasure at seeing me so soon and in having me with him in his last hours, and firmly rejected all expectation and hope of recovery. He had lost all the irritable feeling to which he was very liable, and which generally accompanies paralytic complaints. His own conviction that he was a dying man almost persuaded me that the brilliancy of his mind was a lightening before death.’

The next day he was not only amused but interested deeply with the dissection of a torpedo made by Dr. Davy in an adjoining room.

On the night of March 31, having gradually got worse, he told Dr. Davy he was sure he should die. ‘He took leave of me most tenderly, kissed my cheek, and bade God bless me. I believed that now indeed I was about to lose him and that I should never again hear his voice of kindness. During the night when I went to him he still breathed. The following morning, when I drew back his curtains, he expressed great astonishment at being alive. He said that he had gone through the whole process of dying, and that when he awoke he had difficulty in convincing himself by experiments that he was in his earthly existence. He added that his being alive was quite miraculous, and that he now began to think his recovery not impossible, and that it might be intended by Divine Providence that his life should be prolonged for purposes of usefulness.

‘From this day he pretty rapidly improved; as he mended the sentiment of gratitude to Divine Providence was overflowing.’ On April 20 he wrote his last note at the end of a letter of Dr. Davy’s.

‘My dear Sister,—I am very ill, but, thanks to my dearest John, still alive. God bless you all!—H. Davy.’ ‘He would have said more, but his feeble hand failed him.’

On April 30 he was able to leave Rome for Switzerland. He stayed a week at Genoa and on May 28 he reached Geneva, and there first heard of the death of Dr. Young, ‘which affected him in a manner almost unaccountable.’ He dined early and was read to afterwards; at half-past nine he wished to be left alone, ‘and I took leave of him,’ says Dr. Davy, ‘for the night. At half-past two his servant called me. He was insensible, and in a few minutes he expired.’

For the last half-century general opinion has been so charmed by the simple greatness of Faraday, that even the genius of Davy with his love of original research has been partially eclipsed. But, as time lessens the effect of the contrast, the reputation of Davy will recover its former brightness, and the picture drawn of him by Mr. Poole will not be looked on as due to the partiality of his oldest and most attached friend.

‘Although the most friendly intercourse existed between us for thirty years, I fear I have little else to communicate than to bear testimony to his general intellectual elevation and to the warmth, sincerity, and simplicity of his heart. I was first introduced to him at the Medical Pneumatic Institution at Clifton in, I think, 1799, where I inhaled his nitrous oxide with the usual extraordinary and transitory sensations; but the interesting conversation, manners, and appearance of the youthful operator were not transitory—nay, riveted my attention—and we soon became friends.

‘From that time to his death no interruption of the most cordial goodwill and affection occurred between us. Neither the importance of his discoveries nor the attentions of the exalted in rank or science, whether as individuals or bodies, nor the honour conferred on him by his sovereign, made the least alteration in his personal demeanour or in the tone of his correspondence. No man was ever less spoiled by the world. The truth is, though he conformed to the world and paid due deference to those men and things which are deferred to by the world, his delight was in his intellectual being. He felt that he had the power of investigating the laws of nature beyond that entrusted to the generality of men, and the success with which he acted on this impulse increased his confidence. During his last visit to me in November 1827, when in a very weak state of health, he more than once said, “I do not wish to live as far as I am personally concerned; but I have views which I could develope, if it please God to save my life, which would be useful to science and to mankind.” Indeed, to be useful to science and to mankind was that in which he gloried, to use a favourite word of his. He was enthusiastically attached to science and to men of science, and his heart yearned to be useful to mankind, and particularly to the humblest of mankind. How often have I heard him express the satisfaction which the discovery of the safety lamp gave him. “I value it,” he said, “more than anything I ever did.”

‘However his circumstances and situation in society altered, his labours and zeal in the pursuit of science were throughout his life undiminished.

‘What from my earliest knowledge of my admirable friend I considered his most striking characteristic was the quickness and truth of his apprehension. It was a power of reasoning so rapid when applied to any subject, that he could hardly himself be conscious of the process, and it must, I think, have been felt by him as it appeared to me pure intuition. I used to say to him, “You understand me before I half understand myself.”

‘If his mind had been given in that direction he would probably have ranked high among our poets. I recollect hearing perhaps the greatest living poetic genius (Coleridge) say, “Had not Davy been the first chemist, he probably would have been the first poet of his age.”

‘No man was less a sectarian, if I may use the expression, in religion, in politics, or in science. He regarded with benevolence the sincere convictions of any class on the subject of religion, however they might vary from his own. In politics he was the ardent friend of rational liberty; he gloried in the institutions of his country and was anxious to see them maintained in their purity by timely and temperate reform. Men of science, wherever situated, he considered fellow-subjects of one great republic spread over the world. As to his amusements he would say, “It is not the sport only, though there is a great pleasure in successful dexterity, but it is the ardour of the pursuit, the pure air, the contemplation of the fine country, the exercise, all which invigorate the body and excite the mind to its best efforts.”

‘When he made his last visit to me in 1827, on his arrival he said, “Here I am, the ruin of what I was.” But nevertheless the same activity and ardour of mind continued, though directed to different objects.

‘He was not only one of the greatest but one of the most benevolent and amiable of men.’