Θ Α CATECHISM OF CHEMISTRY: BY SAMUEL PARKES, F.L.S. G.S. &c. A NEW EDITION, REVISED THROUGHOUT, CORRECTED, AND CONSIDERABLY ENLARGED, BY WILLIAM BARKER, M.B. OF TRINITY COLLEGE, DUBLIN. LONDON: PRINTED FOR SCOTT, WEBSTER, AND GEARY, CHARTERHOUSE SQUARE. 1837. ADVERTISEMENT. HAVING undertaken to prepare, for the press, a new edition of Mr. Parkes' Chemical Catechism, the Editor has carefully kept in view the objects for which the work was originally designed, and endeavoured to render it suitable for those who are desirous to become acquainted with the first elements of the Science. As many and important changes have taken place in the different branches of Chemistry, especially in nomenclature and classification, since the publication of the last edition prepared by Mr. Parkes, the present Editor, as far as was consistent with retaining the character and plan of the original work, has altered and revised it throughout, so as to adapt it to the present state of chemical science. iv In the late editions of this work the text was much encumbered with a mass of notes, sometimes useless, and frequently trifling and irrelevant, the notes have consequently been considerably curtailed in the present edition, and none retained or added which did not seem necessary to illustrate or elucidate the text. The order of the chapters has been also altered; the chapter on Chemical Attraction, which, in the former editions was placed at the end, has been placed in the beginning of the work, and the chapters on Atmospheric Air and Water have been incorporated with those which explain the nature of the elements which compose them. The additional notes have been almost wholly omitted, and in their place an Appendix has been substituted, containing details of some important chemical manufactures, and the discussion of some subjects which could not, with propriety, have been introduced into the text. Dublin, June, 1837. |