Laughing Gas (1914 film) squabbling. The dentist arrives, and his first patient goes in, obviously in pain. The dentist prepares the nitrous oxide anaesthesic (also known commonly as "laughing gas" due to its effects prior to and after unconsciousness). With the man unconscious he pulls his tooth, but then he can't get him to wake up. He calls for Charlie and when he arrives the dentist runs off. Charlie tries to wake him and eventually tries hitting his head with a mallet. The man revives but starts laughing. Charlie knocks him out with the mallet. The dentist then returns and Charlie is sent to
Amount of substance in use in chemical engineering in the United States is the pound-mole, having the symbol lb-mol. One pound-mole is . When quoting an amount of substance, it is necessary to specify the entity involved, unless there is no risk of ambiguity. One mole of chlorine could refer either to chlorine atoms, as in 58.44 g of sodium chloride, or to chlorine molecules, as in 22.711 liters of chlorine gas at STP. The simplest way to avoid ambiguity is to replace the term "substance" by the name of the entity or to quote the empirical formula. For example: Amount of substance