Since the introduction of barbital (veronal) in 1903 by Fischer and von Mering,1the drug has found wide clinical application; but it is not without danger, as evidenced by the numerous reports of acute barbital poisoning ensuing from its use. Fischer and von Mering2showed definitely that the drug is slowly (60 per cent in five days) excreted, unchanged in the urine. Other authors, notably Fischer and Hoppe,3von Molle,4Authenrieth,5Bachem,6Halberkann and Reiche,7Marc Reinert,8and Gower and Tatum,9have confirmed this observation. In 1922, Parsons and Tatum10suggested the use of barbital as an anesthetic in laboratory experiments on the lower animals, particularly the dog. We have used the drug many times on the dog and find that after moderate doses the recovery time is very long; i.e., from thirty to forty hours after a dose of