The laboratory in Dublin, which has been enlarged, so as to hold 550 people, will not hold half the persons who desire to hear my lectures. The 550 tickets issued for the course by the Dublin Society at two guineas each were all disposed of the first week, and I am told now that from ten to twenty guineas are offered for a ticket. This is merely for your eye; it may please you to know that your son is not unpopular or useless. Every person here, from the highest to the lowest, shows me every attention and kindness. I shall come to see you as soon as I can. I hear with infinite delight of your health, and I hope Heaven will continue to preserve and bless a mother who deserves so well of her children. I am, your very affectionate Son, H. DAVY. During 1811 he made the acquaintance of Mrs. Appreece, the daughter and heiress of Charles Carr, of Kelso, and about the end of the year probably he wrote to his mother: MY DEAR MOTHER,--You possibly may have heard reports of my intended marriage. Till within the last few days it was mere report. It is, I trust, now a settled arrangement. I am the happiest of men in the hope of a union with a woman equally distinguished for virtues, talent, and accomplishments. * * * * * You, I am sure, will sympathise in my happiness. I believe I should never have married but for this charming woman, whose views and whose tastes coincide with my own, and who is eminently qualified to promote my best efforts and objects in life. I am, your affectionate Son, H. DAVY. He wrote to his brother, at that time a medical student at Edinburgh: MY DEAR JOHN,--Many thanks for your last letter. I have been very miserable. The lady whom I love best of any human being has been very ill. She is now well and I am happy. Mrs. Appreece has consented to marry me, and when the event takes place I shall not envy kings, princes, or potentates. I am, my dear Brother, ever most affectionately yours, H. DAVY. The Laboratory Note-Book at this time contains very little work. On February 21, 1811, he had a paper read to the Royal Society on a ‘Combination of Oxymuriatic Gas and Oxygen Gas, called Euchlorine.’ In July the action of chlorine on carbonic oxide, exposed for hours to bright sunshine, was examined. He wrote, ‘The new gas seems to consist of equal volumes of chlorine and carbonic oxide condensed to one volume.’ On August 7 Davy wrote in the Laboratory Book, ‘To get nitrous oxide, nitrous gas, and very pure chlorine for experiments. To try to decompose nitrogen or to combine it with _chlorine_.’