11. Laboratory technique: Ring test for indol, [by] S. B. Grubbs and Edward Francis; Collodium sacs, [by] S. H. Grubbs and Edward Francis; Microphotography with simple apparatus, [by] H. B. Parker. Bookmark Corporate/Agency Authors: Hygienic Laboratory, Public Health and Marine Hospital Service, and Treasury Department Publisher: Hygienic Laboratory Date: May, 1902