* hydrocarbonate
**Water gas prepared by passing steam over charcoal/coke. Alternatively prepared from unspecified alcohol and sulphuric acid. 
**Hydrocarbonate was recognized to brighten venous blood and compete with oxygen around 1796, although credit is widely awarded to Claude Bernard's work in the mid-1850s. 
*hydrocarbonous acid
* heavy inflammable air
*carbonated hydrogene
* carbonic oxide / protoxide
**William Cruickshank discovered the composition of carbon monoxide and named it gaseous oxide of carbon. Cruickshank recognized water and hydrogen were not a constituent of the combustible base which contained the same ingredients as carbonic acid, although containing less oxygen. 
**Carbonic oxide was identified in the intestine of cattle in the 1800s, marking a trace origin for endogenous carbon monoxide.
*carbonous oxyd
**The name carbonous oxyd relative to carbonic acid was once considered analogous to nitrous oxide to nitric acid based on the oxide not having sufficient oxygen to form the acid.