vi ADVERTISEMENT TO THE FIRST EDITION. thoughts and mode of arrangement resemble those adopted by that distinguished philosopher in his Introduction to the Study of Chemical Philosophy. The second Edition of that work was published so far back as 1843; and even if the work itself had not been long out of print, the progress of science would have detracted greatly from its utility as a text-book. The adaptation of that work to the systematic teaching of the present day would have involved changes of an extensive character: moreover, every teacher who takes an interest in the progress of his class has his own views and methods. The Author, therefore, judged it better, after much consideration, to bring out a new work, leaving untouched that of his late Master as the true exponent of his views upon some of those branches of science which his researches had contributed to advance and adorn. The Author cannot omit to avail himself of the present opportunity of expressing his obligations to his friend, Mr. C. Tomlinson, for many valuable suggestions, and for the warm interest which he has taken in the progress of the work, but more especially for the devotion of no inconsiderable portion of time and labour to the revision of the proof-sheets. King's College, London, March, 1855. TABLE OF CONTENTS. I Chemical Distinction of Bodies into Elements and Compounds 6 General Characters of Acids, Alkalies, and Salts 7 Characters of Chemical Attraction 9 Law of Definite Proportions. 10 Law of Multiple Proportions 13 Combining Proportions-Equivalents-Atoms PAGE Weights and Measures-Specific Gravity 17 English System of Weights and Measures TABLE OF CONTENTS. ix NO. OF 73 Separation of Salts by the process of Crystallization 74 Sudden Crystallization-Nuclei 75 Circumstances which modify Crystalline Form 76 Change of Bulk in the act of Solidification. 88 Influence of Light in producing Chemical Changes 90 Theories of Light-Undulations 91 Illustration of Undulations from Sound 92 Varieties of Sound-Quality-Pitch. 93 Mechanism of Undulation 94 Transparency and Opacity 95 Law of the Diminution of Light by Distance 103 Wollaston's Method of ascertaining Refractive Power 104 Prismatic Analysis of Light. 110 Change in the Refrangibility of Light-Fluorescence 111 Complex Nature of Radiant Force • 205 |