INTENDED FOR THE INSTRUCTION AND ENTERTAINMENT OF YOUNG PEOPLE: IN WHICH THE FIRST PRINCIPLES OF NATURAL AND EXPERIMENTAL PHILOSOPHY ARE FULLY EXPLAINED. VOL. V. OF OPTICS AND MAGNETISM. Conversation, with the habit of explaining the meaning of 1 EDGEWORTH'S PRACTICAL EDUCATION. By the Rev. J. JOYCE. NEW EDITION, CORRECTED AND IMPROVED. 1 LONDON: PRINTED FOR J. JOHNSON, NO. 72, ST. PAUL'S CHURCHYARD. MARVARD COLLEGE LIMATY THE ED EST OF THEOORE JEWETT EASTMAN 531 Printed by S. Hamilton, Weybridge. ADVERTISEMENT. In presenting to the public the concluding volumes of the SCIENTIFIC DIALOGUES, the Author cannot but acknowledge, with sentiments of gratitude, the favourable reception which the former parts of the work have experienced. He trusts that the several subjects comprised in these last volumes, will have an equal claim to the candour of those who are engaged in the arduous but honourable employment of education. It will be seen that it was quite impossible to include in the six volumes the |