CONTENTS. 
Page. 
Part I. Introduction 13 
I. Importance of complete and thorough analyses 13 
II. Object and scope of the present treatise 19 
III. Statement of analyses 21 
IV. Time needed for making an analysis 22 
V. Two useful aids in chemical manipulation 23 
VI. Limits of allowable error in summation of results 24 
VII. Quality of reagents 25 
VIII. Preliminary qualitative analysis 26 
Part II. Methods 27 
I. Introductory remarks 27 
II. Specific gravity 28 
By suspension in water 28 
Ordinary method 28 
Penfield's method 29 
Pycnometer method 29 
Heavy solutions not suitable for rocks 31 
III. Preparation of sample for analysis 31 
Quantity of rock to be crushed 31 
Crushing 31 
Grinding 31 
Weight of ground sample 32 
IV. Water — hygroscopic, zeolitic, crystal 32 
Importance of employing air-dry powder for analysis. . 32 
Temperature of drying 33 
Cautionary hints 33 
Procedure in special cases 34 
Argument in favor of including hygroscopic water in 
summation 35 
Separate entry of hygroscopic and combined water 36 
Is all true hygroscopic water expelled at 100° 36 
Apparatus for the direct determination of water at different 
temperatures 36 
V. Water — total or combined : 38 
Arguments against ' ' loss on ignition ' ' method 38 
Direct weighing of the water without the use of absorption 
tubes — 
Penfield's methods 38 
For minerals easily deprived of their water 38 
For minerals not easily deprived of their water 39 
Direct weighing of the water in absorption tubes 40 
Penfield's procedure 40 
Gooch's apparatus 41 
Chatard's apparatus 45 
Merits of the above three forms of apparatus 45 
Jannasch's methods 45 
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