... respiration. Animals consume the oxygen of the atmosphere, and give off carbonic acid; while plants take up the carbonic acid, and restore to animals the oxygen, thus affording an admirable example ... in a weak acid, (one part muriatic acid and six parts water,) and it can then be bent in any direction. In this experiment, the acid has removed the earthy matter, (carbonate and phosphate ... Define an organ. What is the action of an organ called? Give examples. Mention other examples. 26. What is an apparatus? Give an example 27. How is the term system applied? 19 28. A TISSUE is a...