PREFACE. V % Science ; by this means, the Reader will mme to poflefs all the new and progres sive observations, diScoveries, and im provements, almolt as Soon as they are publifhed abroad; particularly thoSe contained in the Journal called Bergman- ijcher Journal, and the Chemical Journal of Crell—■—Works, which convey very ufeful information on fubje&s relat ing to Chemiftry and Mineralogy, and hence, I hope, not unacceptable to thofe who purfue thefe Hudies. I intend that the firfl Number fhall contain an account of Such mineral fubftances, and Such improvements, as have been lately pub- lifhed abroad, and'were not in my pos- feflion when I finifhed this Work; Se veral of which, I have found in Some excellent books of Gmelin and Suckow, and other eminent authors in Germany. f a 3 Various