The state of his health induced him to perform a tour in Italy, during which he had a severe ill ness at Naples, and on his return to Munich in 1799, he found himself unfit for active duty, and devoted himself to the preparation of the first five of his " Essays." In 1795 he came over to England with the view of publishing his Essays, and drawing the attention of the country to the amelioration of the condition of the lower orders. In 1796, he paid a visit to Lord Pelham, the Irish secretary: and such was the value of the im provements n hich he suggested on some of the public establishments in Dublin, that he was elected a member of the Royal Irish Academy, and received the public thanks of the Lord Lieu tenant, and of the Lord Mayor of Dublin.
In 1796 he established two biennial prizes of the value of about 60 guineas, for the most im portant discoveries on light and heat; the one to be adjudged by the Royal Society of London, and the other by the American Academy of Sciences. An account of this prize has already been given in our article SoelETIEs, Vol. XVII.
In consequence of the advance of General Mo reau to the confines of Bavaria, the Elector was obliged to fly into Saxony. At such a crisis the services of Count Rumford were required. After the battle of Friedberg, he took the command of the Bavarian army, and he succeeded in preventing both the Austrians and the French from entering Munich. When the Elector returned to Munich, Count Rumford was placed at the head of the gen eral police of Bavaria, but the duties of his office made such an inroad upon his health, that he was appointed the Bavarian Minister at the British court, a situation, however, which was found to be incompatible with his character as a British sub ject. Ile therefore continued his residence in England as a private individual, where lie pro jected and established the Royal Institution of Great Britain.
In the year 1800, Count Rumford paid a visit to Edinburgh, where he was consulted respecting the abolition of mendicity, and reformed the culinary establishment of Heriot's Hospital. On this occa sion he was made an honorary member of the Royal Society of Edinburgh, and of the Royal Col lege of Physicians. The American government offered him, about this time, an honorable estab lishment, but his engagements in Europe were in compatible with the acceptance of it.
With the view of residing permanently in Eng land, he fitted up a house at Brompton with every contrivance for hospitality and luxury, but before it was finished the serenity of his mind seems to have been disturbed by some imaginary evils. He
therefore quitted England in 1802, spending the spring in Paris and the summer in Munich. In 1803 he made a tour in Switzerland and Bavaria. accompanied by Madame Lavoisier, whom he mar ried on their return to Paris; but this connexion was not a happy one, and the parties soon sepa rated. The count retired to Auteuil, about Four miles from Paris, and spent his latter years almost in solitude; and though he had been elected one of the eight foreign associates of the Institute, yet he did not even attend its sittings. He enjoyed a pen sion of X1200 a year from the Bavarian govern ment, and spent his time in the improvement of his grounds and in various mechanical and philosoph ical pursuits. In the autumn of 1814 he intended to return to England; but he was seized with a low fever, which carried him off on the 21st of August, in the 62c1 year of his age, leaving behind him an only daughter.
The following is a list of the principal writings of Count Rumford: 1. New Experiments on Gunpowder, Philosophi cal Transactions, 1781, p. 23.
2. New Experiments upon Heat, Id. 1786, p. 273.
3. Experiments on Dephlogisticated Air, Id. 1787, p. 84.
4. Experiments on the Absorption of Moisture from the atmosphere by various substances, Id. p. 240.
5. Experiments on heat, Id. 1792, p. 48.
6. Description of his Photometer. Id. 1794, p. 67.
7. Experiments on the Force of Gunpowder, Id. 1797, p. 272.
8. On the Source of Heat from Frictiin, Id. 1798, p. 80.
9. On the Chemical Properties of Light, Id. 1793, p. 449.
10. On a Phenomenon on the Glaciers of Cha mouny, Id. 1804, p. 23.
11. On the Nature of Heat,and the mode of its Communication, Id. 1804.
12. His ESSAYS, in 4 vols. tvo• Lond. 1795-1800. These Essays, which are '8 in number, were re printed in France and Ge•many.
Count Rumford communicated various papers to the Memoirs of the AVatPnal Institute of France, re lating to heat and liglt• in papers. which are nine in number, are puhlished n vols. vi. vii. and years 1803 and 1807. An account of several of his discoveries and inventions will be found in this work, under the articles GuxrownEn, Vol. X. lIsAT, Vol. X. p. 274; METEORO