27 



later stages of labor, since it causes contraction of the 

 muscles of the uterus. 



The following drugs, Nos. 6-12. are used as purges. The 

 multiplicity of drugs with similar physiological properties is of 

 assistance to the physician in cases of individual idiosyncrasies 

 to a particular plant. In addition, these drugs have somewhat 

 different properties, all acting as cathartics, but in different ways. 



6. Castor oil. Expressed from the seeds of Ricinus communis L. 



Its purging action is followed by constipation and there- 

 fore it is valuable in cases of diarrhoea. Widely cultivated 

 in tropical and subtropical localities. 



7. Rhubarb. The rhizome and roots of several species of Rheum, 



especially R. officinale Baillon, growing in China and 

 Thibet. It is useful for diarrhoea in children. 



8. Senna. The dried leaves of several species of Cassia. Pre- 



pared as an infusion, fluidextract, syrup; a valuable 

 laxative not followed by constipation. 



9. Cascara Sagrada. The dried bark of Rhamnus Purshiana DC. 



In addition to its purging action it acts as a tonic. Pre- 

 pared as a fluidextract and aromatic extract. Native to 

 Northwestern United States and Canada. 



10. Aloe. Juice of the leaves of Aloe Perryi Baker, A. vera L., 



A.ferox Miller. Prepared as a tincture and pills. Used in 

 cases of chronic constipation. Its purging action is slow. 



11. Jalap. Root of Exogoniiim Jalapa (Nutt. and Core) Baillon. 



Prepared as a fluidextract, tincture, etc. A hydragogue 

 cathartic. 



12. Croton oil. Expressed from the seeds of Croton Tiglium L. 



This probably is the most powerful purgative known. 

 The dosage is very small, large doses being lethal. 



13. Hyoscyamus. The leaves and flowering tops of Hyoscy- 



amus niger L. (Henbane). Prepared as a fluidextract, 

 tincture, etc., it is used in cases of nervous disorder be- 

 cause of its sedative action. Its active principles are at 

 least two alkaloids, hyoscyamine and scopolamine. 

 Widely cultivated in Europe. 



14. Valerian. The rhizomes and roots of Valeriana officinalis 



L. prepared as a tincture. It contains a volatile oil which 

 has sedative properties. 



