Dark nebulae in a Milky Way field

Typed note pasted to photo: "A 3-fold enlargement of ADH 550, a blue-sensitive (103a-0) plate taken by W.D. Victor on a region near 17h 53m, -32.5°, of the Milky Way near the border of Sagittarius and Scorpio, which shows a section that is very much affected by an irregular overlying network of dark nebulosity. The absence of bright nebulosity is quite noticeable. Some of the slight diffuseness of images in the enlargement is produced by the enlarger and is not due to defective optics of the ADH telescope. Taken with the Armagh-Dunsink-Harvard Baker-Schmidt telescope at the Boyden Station of Harvard Observatory, Bloemfontein, South Africa." Written on back: "ADH 550". n/a. Extent: 1 photograph. Size and dimensions of original material: Height 21cm, width 26cm. Condition of original material: Moderate damage (curled, tear, creased, folded, edge damage). Author(s)/Creator(s): English. Scribe(s): Latin. Publisher(s): Left-to-Right. Editor(s): Unrestricted. Volume number: N/a. Original institution reference: PB11_P0451.