Pharmacokinetics of Halothane and Ether.

In 1847 John Snow wrote: "It will be at once admitted that the medical practitioner ought to be acquainted with the strength of the various compounds which he applies as remedial agents, and that he ought, if possible, to be able to regulate their potency. The compound of ether vapour and air is no exception to this rule, although it might be supposed to form one, as the practitioner stands by to watch its effects." It is true today that many practitioners are content to administer drugs without much thought about how or why the drugs produce their effects.