from The Century Dictionary and Cyclopedia
- n. That member of a series of oxids which contains a single oxygen atom combined with a single bivalent atom or with two univalent atoms: applied only to oxids which are not strongly basic or acid.
Sorry, no etymologies found.
The protoxid of tin (SnO) is black, and can be obtained from chlorid of tin, or by _long_ exposure of tin to the atmosphere.
"In the mouth, a suboxid is more likely to be formed than a protoxid, but both are black; sulfur and oxygen are capable of acting on tin under favorable circumstances, such as warmth, moisture, full contact, condensation of elements, and their nascent conditions; the first three are always present in the mouth.