Count Rumford, in the spring of 1793, left Munich for Italy on account of his health. He was absent sixteen months. At Verona the directors of the two great hospitals La Pieta and La Misericordia, containing 350 and 500 poor, accepted his offer to rebuild the kitchens. Seven-eighths of the fire-wood were saved, and he made arrangements to supply the poor with clothing from the Munich House of Industry at a saving of twenty per cent.
On May 11, 1793, Sir C. Blagden, who was travelling with Lord Palmerston, wrote to Sir Joseph Banks from Rome:
Count Rumford is come into Italy. I have just received a very friendly letter from him, in which he desires me to appoint a meeting. It will probably be at Milan.
Three months later he wrote from Augsburg:
Thompson, now Count Rumford, met me by appointment at Pavia. Volta showed us his experiments on animal electricity, and said he had sent off his paper for the Royal Society about three weeks before, probably not time enough for it to be read before the vacation. I thought his experiments proved that there is no particular animal electricity, and that the animals serve only the purpose of very delicate electrometers; but they leave other circumstances unexplained.
On his return to London Sir C. Blagden wrote on November 21 to Sir Joseph Banks:
From Italy I brought two papers by Count Rumford, one on 'Coloured Shadows,' the other on a 'Method of Measuring the Comparative Intensities of the Light Emitted by Luminous Bodies.' In the former he shows neatly enough that the colours ascribed to these shadows depend entirely on comparing them with light of another colour. The method referred to in the second paper is that of the intensity of the shadows produced by the different luminous bodies. These two papers will furnish matter for nearly three meetings of the Royal Society.
Count Rumford had another serious illness in Naples in the early part of 1794. He returned to Munich in August.
He left Munich for London in 1795. He had spent the year after his return from Italy in comparative quiet. He was unfit for public business and he chiefly occupied himself by writing out the results that he had obtained. He thus made a series of essays.
In order to publish these in England and to meet his daughter, who was about to come to him from America, and to recover further his health, he obtained leave of absence from the Elector of Bavaria.