In 1806 and 1807 Count Rumford sought for relief by the pursuit of science. He published in the Memoirs of the mathematical class of the Institute a continuation and extension of his investigations on light and heat. These were in the sixth, seventh, and eighth volumes, and made nine papers. 1. ‘A Description of a New Thermoscope or Differential Thermometer.’ 2. ‘Researches on Heat, Showing the Effect of Difference of Surface on Radiation.’ 3. ‘Further Experiments on the Effect of Blackening the Surface.’ 4. ‘Researches Continued on the Different Properties of Bodies with Respect to Radiation and to Conducting Powers.’ 5. ‘Further Researches on the Passage of Heat through Solids.’ 6. ‘Experiments on the Heat of the Solar Rays.’ 7. ‘Remarks on the Temperature of Water at the Maximum Density.’ He made it 41° F. or 5° C. This paper was published in the ‘Philosophical Transactions.’ 8. On the ‘Dispersion of the Light of Lamps by Screens of Ground Glass, Silk, and so forth, with a Description of a New Lamp.’ He had an illuminator constructed and presented to the Institute. This paper was published in England as his sixteenth essay on the ‘Management of Light in Illuminations.’ 9. On the ‘Cooling of Liquids in Vases of Porcelain, Gilt or not Gilt.’ In October 1806 he gave this sad account to his daughter: MY DEAR CHILD,--This being the first year’s anniversary of my marriage, from what I wrote two months after it, you will be curious to know how things stand at present. I am sorry to say that experience only serves to confirm me in the belief that in character and natural propensities Madame de Rumford and myself are totally unlike, and never ought to have thought of marrying. We are, besides, both too independent, both in our sentiments and habits of life, to live peaceably together--she having been mistress all her days of her actions, and I, with no less liberty, leading for the most part the life of a bachelor. Very likely she is as much disaffected towards me as I am towards her. Little it matters with me, but I call her a female dragon--simply by that gentle name! We have got to the pitch of my insisting on one thing and she on another. It is possible that, had the war ceased raging, and had we gone into Italy, where she is dying to go, and with me too, she having heard me speak much of the delights of that country, she having been very happy, too, in travelling with me in Switzerland, it might have suspended difficulties, but never have effected a cure. That is out of the question. Indeed, I have not the least idea of continuing here, and, if possible, still less the wish, and am only planning in my mind what steps I shall take next--to be hoped more to my advantage. Communication with England is prohibited, and it makes me sad. He wrote more pitiably a year later: Rue d’Anjou, Paris, October 24, 1807.