This is an OCR edition without illustrations or index. It may have numerous typos or missing text. However, purchasers can download a free scanned copy of the original rare book from GeneralBooksClub.com. You can also preview excerpts from the book there. Purchasers are also entitled to a free trial membership in the General Books Club where they can select from more than a million books without charge. Original Published by: G.P. Putnam's sons in 1910 in 150 pages; Subjects: Dust; Bacteriology; History / General; Medical / General; Medical / History; Science / General; Science / Life Sciences / Bacteriology; Science / Environmental Science; Science / Life Sciences / Biology / Microbiology;