NERVO-MUSCULAR STIMULANTS. 429 



4. Measures which influence the Intestinal Glands. a. The 

 secretions of the intestinal glands are moderately increased by 

 Mercurial preparations ; greatly increased by Croton Oil, 

 Elaterium, Colocynth, Jalap, Scammony, and Podophyllin, 

 which no doubt act also upon the vessels and muscles. Jalap 

 and Scammony require to be dissolved in the bile. We 

 have just seen that the saline purgatives are also glandular 

 stimulants, being no sooner absorbed than they are again 

 excreted. This class of purgatives may be called cathartics 

 (naQaipa, I cleanse) ; such of them as produce very watery 

 motions, hydragogue cathartics. 



b. Opium, Lead, and Lime directly diminish the intestinal 

 secretions and promote constipation. Alkalies, Alkaline Earths 

 and their Carbonates interfere with the acidity of the chyme 

 when given in full doses, and thus indirectly arrest the intes- 

 tinal secretions ; whilst, by conversion into sulphates in the 

 bowel, they may become active purgatives. Thus certain saline 

 substances may not only be purgative in more than one way, 

 but may even be purgative and astringent at the same time ; 

 the one effect or the other occurring according to the dose, the 

 patient, and other circumstances which are often obscure. 



6. Measures which influence the Nervo-muscular Structures. 

 Many of the materiae medicae influence the bowels through 

 the mu-scular coat, the nerves, or both. Thus drastics excite 

 intestinal peristalsis and griping even before they have left the 

 stomach, as is seen in Croton Oil. Saline purgatives are 

 believed to have the same effect. It is practically convenient 

 to arrange in a special class those substances which act entirely 

 or chiefly upon the intestinal muscles. 



a. Nervo-muscular Stimulants. These include Rhubarb, 

 Senna, Aloes, Castor Oil, Sulphur, Sugars, Nux Vomica, Rham- 

 nus Frangula, Cascara Sagrada, and Belladonna, and many 

 others. They are best given with carminatives, to prevent the 

 intestinal pain caused by excessive or spasmodic muscular con- 

 traction, popularly known as "griping," which they readily 

 induce. Belladonna appears to act in a different way from 

 the others, by removing the inhibition of the splanchnic ; and 

 ergot by causing anaemia of the muscles. The stool which 

 follows the action of a muscular stimulant is much less watery 

 than that produced by saline or cathartic purgatives, being 

 chiefly the ordinary contents of the small bowel hurried down, 

 unless the drug be given in large doses. For the same reason 

 the disturbance of the portal circulation, liver, the general 

 circulation, and the system as a whole, is less marked. The 

 nervo-muscular purgatives are commonly known as simple 

 purgatives ; and the mildest of them, such as Castor Oil and 



