Note 162 — Chapter XII · SUMMARY.

I may add my own testimony. When the second edition of the "Student's Elements" was passing through the press. I ventured to write to him about one or two petrological details, which I thought might be more precise. Though at that time I had published but few papers, I received more than one kind letter with the request that I would read some of the proof-sheets of the book and suggest alterations.