The plants of the genus Datura are known for their use as hallucinogens and deleriants. The alkaloids produced by the Datura spp. are known as tropanes, and generally occur as either atropine, scopolamine, or hyoscyamine. Atropine is responsible for many of the hallucinatory effects of Datura. Scopolamine and hyoscyamine (while still attributable to the psychoactive effects of Datura) tend to cause more unpleasant effects (such as temporary blindness, as in the case with scopolamine). Tropanes find many uses pharmaceutically. Atropine is the common antidote for most of the nerve-gasses, while scopolamine and hyoscyamine are often used in transdermal patches (much like nicotine patches) to counteract the effects of motion-sickness. The different species of Datura generally contain all three of these tropanes, however, some have varying amounts.