A Dispensatory is a commentary on the Pharmacopoeia. They contain all that the Pharmacopoeia states regarding official drugs and much additional information. They also treat of other drugs not included in the Pharmacopoeia. They are compiled and published as private enterprises and contain a vast amount of information that is invaluable to the student of Materia Medica.

The American Medical Association is maintaining a department for the investigation of unofficial preparations offered the medical profession. The effort is made to eliminate fraud and encourage merit. The remedies included in these volumes are those found to meet certain requirements. It is one of the greatest advances ever made in Materia Medica.