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Faraday passion so ardent, that she for a time doubted her ability to return it with adequate strength. His utterances at this crisis of his life were marked by the delicacy and considerateness which diffused themselves throughout his entire character. She at length yielded, and they were married on 12 June 1821. An entry in a book containing his diplomas ran thus: 'Amongst these records of events I here insert the date of one which, is a source of honour and happiness, for exceeds all the rest. We were married on 12 June 1821.' At the time of their marriage Miss Barnard was twenty-one, while Faraday was thirty. It is pleasant to record the manner in which Davy received the intelligence of the marriage; 'I hope you will continue quite well, and do much during the summer, and I wish you in your new state all that happiness which I am sure you deserve." 'A month after his marriage he made his confession of sin and profession of faith before the Sandemanian Church. When his wife asked him why he had not told her what he was about to do, he only replied, "That is between me and my God"' (, Life and Letters).

Œrsted discovered in 1820 that a freely suspended magnetic needle was deflected by a voltaic current, and soon afterwards the penetrative mind of Wollaston conceived the idea of causing the needle to rotate round the current, and the wire carrying the current to rotate round a magnet. Faraday's attention is soon directed to this question, but before touching it he went through the discipline of writing a 'History of the Progress of Electro-Magnetism.' Immediately afterwards he attacked the subject of 'Magnetic Rotations,' and on the morning of Christmas day he led his young wife into the laboratory, and showed her the revolution of a magnetic needle round an electric current. He had also in the same year made experiments on the vaporisation of mercury at common temperatures, Immediately afterwards, and jointly with Mr. Stoddart, he worked with success on the alloys of steel. A razor made of one of these alloys, and presented to the present writer by Faraday himself, is still in his possession.

We now approach a subject of high importance. In the spring of 1823 Faraday analysed a substance proved by Davy to be the hydrate of chlorine, and which, prior to Davy's experiments, had been regarded as chlorine itself. The paper describing the analysis was looked over by Davy, who suggested on the spot the heating of the hydrate under pressure, in a sealed glass tube. The hydrate fused at a moderate heat, the tube became filled with a yellow gas, and was found to contain an oily liquid. When the end of the tube was broken off an explosion occurred, and the oily matter vanished. Next morning Faraday, writing to Dr. Paris, was able to make the following important communication; 'The oil you noticed yesterday turns out to be liquid chlorine.' Davy, on being informed of what had occurred, immediately applied the method of self-compressing atmospheres to the liquefaction of muriatic gas. Faraday afterwards liquefied chlorine by a compressing syringe, and succeeded in reducing a number of other gases, up to that time deemed permanent, to the liquid condition. He followed up the subject in 1844, and considerably expanded its limits. A sure and certain addition was made to our knowledge of matter by these important experiments. They rendered the conclusion next to certain that all gases are but the vapours of liquids possessing very low boiling points — a conclusion triumphantly vindicated by the liquefaction of atmospheric air, and other refractory gases, in our own day.

The 'Philosophical Transactions' for 1825 contains a paper by Faraday 'On New Compounds of Carbon and Hydrogen.' In it was announced the discovery of benzol, which has been turned to such profitable commercial account as the basis of our splendid aniline dyes. In 1826 he published in the 'Transactions' another paper 'On Sulphonaphthalic Acid,' and afterwards occupied himself with experiments on the limits of vaporisation. In 1823 Sir John Herschel had suggested the use of borate of lead in the manufacture of a highly refractive optical glass. He and Mr. (afterwards Sir James) South had actually succeeded in producing a glass with a refractive index of 1.866. The glass, however, proved too soft for optical purposes. In 1825 a committee, embracing Faraday, Sir John Herschel, and Dollond was formed with a view of pursuing this subject. The experiments were begun at the Falcon Glass Works, but completed in the yard of the Royal Institution. It was at this time that Faraday engaged as assistant Sergeant Anderson of the Royal Artillery, to whose 'care, steadiness, exactitude, and faithfulness in the performance of all that has been committed to his charge,' he avowed his indebtedness. Anderson's sense of duty and obedience was so precise that it was said of him that if the Institution were on fire he would not quench the flame except by Faraday's command. An elaborate paper 'On the Manufacture of Glass for Optical Purposes' formed the material of Faraday's first Bakerian lecture, which was delivered