Sentence:  A smaller plate was immersed, while the combustion was in active operation, in a glass <WSD>jar</WSD> of carbonic acid gas without any diminution of the incandescence of its surface, showing that the combustion is independent of the atmosphere in which takes place. 
Meaning of the word marked with <WSD> tags:  A jar and its contents; as much as fills such a container; a jarful.