Other subjects explored include hydrogen bonding effects on the photochemistry of chromophores in solution, photochemical generation of silicon-centered radicals and their reactions, and photochemical processes at the air-water interface of atmospheric droplets.
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class of psychoactive drugs. It is the world's most widely consumed psychoactive drug, but unlike many other psychoactive substances, it is legal and unregulated in nearly all parts of the world.
1 Other class A drugs include: Methamphetamine, Methadone, Ecstasy and Lysergic Acid Diethylamide (LSD). 2  Class B drugs are very harmful and addictive-this group includes cannabis and the more potent variety skunk. 3  If you are found with cannabis in your pocket you can get up to five years in prison. For example Crack Cocaine is a Class A drug, 'Spice' and 'Mephedrone', cannabis and a large number of synthetic cannabinoids are class B drugs. 2  Ketamine is a currently a class C drug. 3  Class A drugs are the most addictive and harmful and include things like heroin and cocaine.