All the foregoing experiments, on the explosion of inflammable air with common and dephlogisticated airs, except those which relate to the cause of the acid found in the water, were made in the summer of the year 1781, and were mentioned by me to Dr. Priestley, who in consequence of it made some experiments of the same kind, as he relates in a paper printed in the preceding volume of the Transactions. During the last summer also, a friend of mine gave some account of them to M. Lavoisier, as well as of the conclusion drawn from them that dephlogisticated air is only water deprived of phlogiston; but at that time so far was M. Lavoisier from thinking any such opinion warranted, that, till he was prevailed upon to repeat the experiment himself, he found some difficulty in believing that nearly the whole of the two airs could be converted into water. It is remarkable, that neither of these gentlemen found any acid in the water produced by the combustion; which might proceed from the latter having burnt two airs in a different manner from what I did; and from the former having used a different kind of inflammable air, namely, that from charcoal, and perhaps having used a greater proportion of it. FOOTNOTES: [Footnote 16: From _Experiments with Airs--Transactions of Royal Society of London_ (1784).] XV SIR WILLIAM HERSCHEL 1738-1822 _Sir William Herschel was born in Hanover, Germany, November 15, 1738, the son of a bandmaster. At an early age he was compelled to earn his own living by playing in the band of the Hanoverian Guards. In 1766, after some years of financial straits, he found work as an organist at Bath. Studying languages and mathematics without assistance from tutors, he became interested in “the music of the spheres” which developed into a scientific attitude in astronomy. He managed, in spite of his poverty, to construct specula for a telescope and in 1781, with one of his own instruments, he discovered the planet Uranus, one of the most romantic discoveries in the history of science. Among his other discoveries were two of the satellites of Uranus, two more of Saturn, and the fact that the moon was without atmosphere; he also described many of the binary stars, discovered many nebulous stars (which prepared the way for the nebular theory of the universe), and made the inference from the movements of the stars that the whole solar system was rushing towards the constellation of Hercules. After his death, August 25, 1822, his son, Sir John Herschel, continued his work in astronomy._ I THE DISCOVERY OF URANUS[17] ACCOUNT OF A COMET