TRANSCRIBER’S NOTES

1. Table of Contents added by transcriber.

2. All text after the Contents was handwritten.

3. Silently corrected typographical errors and variations in spelling.

4. Retained anachronistic, non-standard, and uncertain spellings as

printed.

5. Footnotes have been re-indexed using numbers.

6. Enclosed underlined text in _underscores_.

Comparison of Methods of Sewage Purification · 第 6 / 6 题