This section is from the book "A Text-Book Of Pharmacology, Therapeutics And Materia Medica", by T. Lauder Brunton. Also available from Amazon: A text-book of pharmacology, therapeutics and materia medica.
[Stimulation is evidenced by a rise of blood-pressure, which disappears on section of the spinal cord below the medulla, and does not occur if the cord has been divided before the injection of the drug. This rule is only partially true, because subsidiary vaso-motor centres occur in the spinal cord itself.]
Irritants of motor centres, p. 176.
Salts of ammonium.
Stimulant action doubtful; slight, and transient.
Large doses of most drugs, such as those in the adjoining column, which stimulate in small doses.
Depression usually occurs in the later stages of the action of such drugs even in moderate doses.