I had to look it up! 😉
Dictionary
Alum
a·lum1
/ˈaləm/
noun: alum; noun: potash alum
- a colorless astringent compound that is a hydrated double sulfate of aluminum and potassium, used in solution medicinally and in dyeing and tanning.
o any of a number of analogous crystalline double sulfates of a monovalent metal (or group) and a trivalent metal.
What is alum used for?
It is aluminum potassium sulfate. This is the type of alum that you find in the grocery store for pickling and in baking powder. It is also used in leather tanning, as a flocculant in water purification, as an ingredient in aftershave and as a treatment to fireproof textiles.
Dave
From: CBQ@groups.io <CBQ@groups.io> On Behalf Of Bob Chaparro via groups.io
Sent: Monday, September 14, 2020 1:35 PM
To: CBQ@groups.io
Subject: [CBQ] Photo: Unloading Alum From CB&Q Boxcar 134010 (1931)
Photo: Unloading Alum From CB&Q Boxcar 134010 (1931)
A photo from the Detroit Public Library:
https://digitalcollections.detroitpubliclibrary.org/islandora/object/islandora%3A230469
Click and hold to enlarge photo.
Caption:
View of two men unloading alum, via a hose, from a railroad freight car during the construction of the Chemical Building in the Springwells Station treatment plant, Detroit water supply system. Printed on front: "City of Detroit. Department of Water Supply. Springwells Station. Chemical Building. Contract No. FC-20. Building construction: W.E. Wood Company. File no. 831. No. 30. Date: 8-6-31. Photo by Manning Brothers." Typed on back: "Unloading first car of alum; air hose suspended from cable."
Alums are a family of chemical compounds. In this case the load probably is a
potassium-based alum used in water treatment.
Bob Chaparro
Hemet, CA