Fig. 1. These graphs illustrate the effect of the concentration effect for two gases that differ significantly in solubility and, therefore, uptake characteristics: the poorly soluble nitrous oxide and the highly soluble diethyl ether. At a 1% inspired concentration, the alveolar concentration (each graph gives the alveolar concentration as a percentage of the inspired concentration) increases faster with nitrous oxide than with ether. However, this differential decreases as the absolute inspired concentration (the values associated with each graph) increases, and at 100% inspired concentration, the increase is fastest and is the same for nitrous oxide and ether. Uptake does not influence how rapidly the alveolar concentration increases. These computer simulations are used with permission from figure 6.2 of Anesthetic Uptake and Action , 1974, 1-371.