CONTENTS. 



PAGE 



INTRODUCTION iii 



CHAPTER I. GENERAL PART. 



Principle of the method 1 



Distilled water 3 



Boric acid 5 



Sodium carbonate 5 



Borax 7 



Methyl alcohol 9 



Formic and hydrofluoric acids. (Other reagents) 11 



The apparatus 12 



The dehydration of borax 15 



Concerning the complete dehydration of borax 20 



Balance and weighing; constants used 23 



CHAPTER II. 



A. The atomic weight of boron 26 



Preliminary experiments 26 



Final determinations 27 



Experiment IV. Na 2 B 4 O 7 : 2NaCl : Na 2 SO 4 27 



Experiments V, IX, X, XI. Na 2 B 4 7 : 2NaF : Na 2 SO 4 31 



Experiment VI. Na 2 B 4 O 7 : Na 2 SO 4 36 



Experiment VII. Na 2 B 4 O 7 : 2NaNO s 37 



Experiment VIII. Na a B 4 7 : Na 2 CO 38 



Tabulation 41 



The atomic weight of boron referred to "borax glass" 42 



B. The atomic weight of fluorine 44 



CHAPTER III. 



Review of previous determinations of the atomic weight of boron 48 



General considerations 48 



A. The determination of water in crystallized borax 51 



B. The analysis of anhydrous borax (the distillation method) 53 



C. The titration of borax 58 



Summary 63 



v 



