'At the same time that he gratified my desires as to scientific employment, he still advised me not to give up the prospects I had before me, telling me that science was a harsh mistress and, in a pecuniary point of view, but poorly rewarding those who devoted themselves to her service. He smiled at my notion of the superior moral feelings of philosophic men, and said he would leave me to the experience of a few years to set me right on that matter.' (March 1, 1813.)

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Soon after the interview Faraday was installed, at Davy's recommendation, as assistant in the Laboratory at the Royal Institution at the salary of 25s. a week, with two rooms at the top of the house.

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Now Faraday felt himself for the first time in his life in a congenial atmosphere, and only six days after his installation he writes to Abbott in spirits as high as in his latter letters they had been depressed; full of his chemical work, making a compound of sulphur and carbon, a combination which has lately occupied in a considerable degree the attention of chemists.' Only a few weeks later he was employed by Davy to assist him in the investigation of the most explosive body even now known to chemists-chloride of nitrogen, and this fact speaks volumes for Sir Humphry's opinion of his scientific knowledge as well as of his manipulative skill. Thus we find Faraday in these first few weeks of his scientific career plunged at once into the most difficult of experimental investigations. He was not daunted by severe and unlooked-for explosions which tore open his hand and cut his eye, and in which the more experienced Davy received some severe wounds; he prosecuted his experiments with this terrible compound, estimating its specific gravity, and ascertaining its chemical properties. Not only did he work with devotion in the prosecution of Davy's original researches, but he began to consider the best means of bringing the results of scientific investigation before the minds of others, and in some of his letters his remarks on the appliances of experimental lectures show, as Dr. Bence Jones remarks, the keenness of his observation, the abundance of his ideas, and the soundness of his judgment. No one who is familiar with Faraday's mode of lecturing, and with the excessive pains which, even to the last, he used to take about every minute detail of his experimental illustrations, can fail to observe that the ideas which he consistently carried out were mainly formed in early life. Thus

*

We know as a fact that Faraday always tried the stopper of every bottle he was to use, before the lecture began, so that no delay might be caused from the stopper being fixed when the reagent was wanted during the lecture.

in 1813, when twenty-one, he writes on this subject to Abbott:

'When an experimental lecture is to be delivered, and apparatus is to be exhibited, some kind of order should be observed in the arrangement of them on the lecture table. Every particular part illustrative of the lecture should be in view, no one thing should hide another from the audience, nor should anything stand in the way of or obstruct the lecturer. They should be so placed, too, as to produce a kind of uniformity in appearance. No one part should appear naked and another crowded, unless some particular reason exists and makes it necessary to be so. At the same time, the whole should be so arranged as to keep one operation from interfering with another. If the lecture table appears crowded, if the lecturer (hid by his apparatus) is invisible, if things appear crocked, or aside, or unequal, or if some are out of sight, and this without any particular reason, the lecturer is considered (and with reason too) as an awkward contriver and a bungler.'

His description of his ideal lecturer is so perfect and gives so true a picture of Faraday himself, as well as of his early easy style, that we cannot resist the temptation of a quotation, especially as the reputation which Faraday gained in the world in general as a lecturer was as great as that which he possessed amongst men of science as an original investigator.

The most prominent requisite to a lecturer, though perhaps not really the most important, is a good delivery; for though to all true philosophers science and nature will have charms innumerable in every dress, yet I am sorry to say that the generality of mankind cannot accompany us for one short hour unless the path is strewed with flowers. In order, therefore, to gain the attention of an audience (and what can be more disagreeable to a lecturer than the want of it?) it is necessary to pay some attention to the manner of expression. The utterance should not be rapid and hurried and consequently unintelligible, but slow and deliberate, conveying ideas with ease from the lecturer, and infusing them with clearness and readiness into the minds of the audience. A lecturer should endeavour by all means to obtain a facility of utterance, and the power of clothing his thoughts and ideas in language smooth and harmonious and at the same time simple and easy. If his periods are long, or obscure, or incomplete, they give rise to a degree of labour in the minds of the hearers which quickly causes lassitude, indifference, and even disgust.

A lecturer should appear easy and collected, undaunted and unconcerned, his thoughts about him, and his mind clear and free for the contemplation and description of his subject. His action should not be hasty and violent, but slow, easy, and natural, consisting principally in changes of the posture of the body, in order to avoid the air of stiffness or sameness that would otherwise be unavoidable. His whole behaviour should evince respect for his audience, and he should in no case forget that he is in their presence.

'He should exert his utmost effort to gain completely the mind and

attention of his audience, and irresistibly to make them join in his ideas to the end of the subject. He should endeavour to raise their interest at the conimencement of the lecture, and by a series of imperceptible gradations, unnoticed by the company, keep it alive as long as the subject demands it. No breaks or digressions foreign to the purpose should have a place in the circumstances of the evening; no opportunity should be allowed to the audience in which their minds could wander from the subject, or return to inattention and carelessness. A flame should be lighted at the commencement and kept alive with unremitting splendour to the end.

An experimental lecturer should attend very carefully to the choice he may make of experiments for the illustration of his subject. They should be important, as they respect the science they are applied to, yet clear, and such as may easily and generally be understood. They should rather approach to simplicity, and explain the established principles of the subject, than be elaborate, and apply to minute phenomena only.

Let your experiments apply to the subjects you elucidate; do not introduce those which are not to the point.

Apt experiments (to which I have before referred) ought to be explained by satisfactory theory, or otherwise we merely patch an old coat with new cloth, and the whole (hole) becomes worse. If a satisfactory theory can be given, it ought to be given. If we doubt a received opinion, let us not leave the doubt unnoticed, and affirm our own ideas, but state it clearly, and lay down also our objections. It' the scientific world is divided in opinion, state both sides of the question, and let each one judge for himself, by noticing the most striking and forcible circumstances on each side. Then and then only shall we do justice to the subject, please the audience, and satisfy our honour-the honour of a philosopher.'

In the autumn of 1813 Davy proposed to Faraday to take him abroad in the capacity of amanuensis and scientific assistant, and on October the 13th the party left England. A Journal written during this foreign tour, which lasted a year and a half, is remarkable for the minuteness of the description of all he saw, and for the cautious silence regarding those he was with. Full particulars of Sir Humphry's scientific work are, however, given. The letters, chiefly written to his mother and to his friend Abbott, exhibit his warm heart, his affectionate attachment to home and friends, and show his constant desire for self-improvement :

'I am almost contented,' he writes to his mother, 'except with my ignorance, which becomes more visible to me every day, though I endeavour as much as possible to avoid it. I have learned just enough. to know my own ignorance, and to be ashamed of my defects in everything; I wish to seize the opportunity of remedying them . . . added to which the glorious opportunity I enjoy of improving in the know

ledge of chemistry and the sciences continually determines me to finish this voyage with Sir Humphry Davy.'

Many interesting extracts from his Journal are given in the Biography. The following note shows that the rising philosopher was by no means destitute of a keen appreciation of the ludicrous:

'I cannot help dashing a note of admiration to one thing found in this part of the country-the pigs! At first I was positively doubtful of their nature; for, though they have pointed noses, long ears, rope-like tails, and cloven feet, yet who would imagine that an animal with a long thin body, back and belly arched upwards, lank sides, long slender feet, and capable of outrunning our horses for a mile or two together, could be at all allied to the fat sons of England! When I first saw one, which was at Morlaix, it started so suddenly and became so active in its motions on being disturbed, and so dissimilar in its actions to our swine, that I looked out for a second creature of the same kind before I ventured to decide on its being a regular or an extraordinary production of nature; but I find they are all alike, and that what at a distance I should judge to be a greyhound, I am obliged, on near approach, to acknowledge a pig.'

As a characteristic specimen of the letters written during his journey to his mother, we may quote the following, written from Rome on April 14, 1814 :—

'When Sir H. Davy first had the goodness to ask me whether I would go with him, I mentally said, "No, I have a mother, I have "relations here," and I almost wished that I had been insulated and alone in London; but now I am glad that I have some left behind me on whom I can think, and whose actions and occupations I can picture to my mind. Whenever a vacant hour occurs I employ it by thinking on those at home. In short, when sick, when cold, when tired, the thoughts of those at home are a calm and refreshing balm to my heart. Let those who think such thoughts are useless, vain, and paltry think so still. I envy them not their more refined and more estranged feelings. For me I still cherish them, in opposition to the dictates of modern refinement, as the first and greatest sweetness in the life of man.'

Faraday describes in clear and precise scientific language the results of Davy's experiments, made in Paris together with the French savans on the newly-discovered element Iodine; and he adds that the finding of this substance in matters so common and supposed so well-known as the ashes of sea-weed must be a stimulus of no small force to the inquiring minds of modern chemists, whilst it is a proof of the imperfect state of the 'science, and every chemist will regard it as an addition of no small magnitude to his knowledge, and as the forerunner of a 'great advance in chemistry.' He visits in Paris with Davy

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the laboratories and lecture-rooms of the great men there boldly holding up the torch of science to civilisation and progress amidst the din and horrors of war; and he appears (like a sensible man and a philosopher) much more interested by the result of an experiment made with Chevreul's Voltaic pile proving the probable elementary nature of the new substance now called iodine,' than with the sight of the Emperor in full state sitting in the corner of his carriage, covered and almost hidden from sight by an enormous robe of ermine, and his face overshadowed by a tremendous plume of feathers that descended from a velvet hat. At the end of December they left Paris, went south, and stayed some time at Montpellier, where Davy continued his experiments on iodine, but failed to detect its presence in the sea-plants of the Mediterranean. Pushing further south to Florence, they visited the celebrated Academy del Cimento. Here was much to excite interest: Galileo's first telescope, with which he discovered Jupiter's satellites, and the great burning-glass of the Grand Duke of Tuscany. With this celebrated lens Davy made some experiments on the composition of the diamond. Long ago in 1694 had Averami and Targioni burnt diamonds with this same great lens before the astonished Como III. Lavoisier, too, in 1773 proved that carbonic acid was formed when diamonds are burnt, and henceforward this brilliant lustrous gem, the hardest of known substances, was admitted to be identical in its chemical nature with soft black soot. Still it was doubted whether the diamond did not contain hydrogen as well as carbon, and, although Smithson Tennant had shown in 1796 that charcoal and diamond give on oxidation with nitric acid equal quantities of carbonic acid, it yet remained for Davy to settle the question of the composition of the gem. The diamond heated in the focus of the large lens glowed brilliantly with a scarlet light, carbonic acid gas was formed, and no vapour or any signs of the formation of water could be perceived, so that as yet it ' appears that the diamond is pure carbon.' Having finished these experiments, they bid adieu to the Academy del Cimento and went forward to Rome. From Rome they visited Naples, and, having explored Vesuvius, returned northward. The subject of the following entry of his diary on Friday, June 17th, at Milan might form a fit material for a picture:- Saw M. Volta, who came to Sir H. Davy: an hale elderly man, bearing the red ribbon, and very free in conversation.' What if the Volta, then sixty-eight years of age and in the height of his fame, could have foreseen that the humble attendant of the brilliant English chemist was the man destined to place the

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