480 



HEALTH AND DISEASE 



Opium as imported is a Ijlackish-brown, pasty-looking substance. The 

 chemist is able to separate from it some nineteen or twenty alkaloids, of 

 which the chief are morjihia and codeia. The preparations used in veteri- 

 nary practice are the gum, the powder, tincture (laudanum), morphia, and 

 occasionally codeia. 



When an aqueous preparation is required the extract is rubbed down 

 with hot water. The compound tincture (paregoric elixir) is also some- 

 times prescribed. 



The chief method of administering morphia is by subcutaneous injec- 

 tion. This course is adopted as a 

 matter of convenience, and not, as 

 in the human subject, to avoid those 

 derangements of the stomach and 

 bowels which so commonly follow its 

 use when given Ijy the mouth. 



Action and Uses. — Externally 

 tlie tincture and extract of opium are 

 used to allay pain, and it is gener- 

 ally believed that greater anodyne 

 effects are produced upon an abraded 

 surface than when ajDplied to an 

 unbroken skin. In inflammatory 

 cedema, and sprains to tendons, joints, 

 and contusions, its application in con- 

 junction with acetate of lead and 

 spirit of wine has long been resorted 

 to on account of its soothing and 

 sedative properties. 



Internally administered, opium af- 

 fects horses in different ways and in 

 proportion to the dose. In small doses 

 it is a stimulant. Long continued it becomes astringent and induces con- 

 stipation, although a medium dose be employed. Its effect in controlling pain 

 and spasm of the intestine has been recognized for ages. It is also employed 

 in diarrhoea and other diseases in which purging is a prominent symptom. 



Large doses are sometimes given to restive horses that will not submit 

 to operation, and that for special reasons cannot be submitted to other 

 forms of restraint; and in a few instances only is the same degree of excite- 

 ment observed to follow its use, as marks its immediate effects on man. 



Belladonna, and Atropia, its active principle, belong to the same 

 class of anodyne and sedative drugs as ojDium, and may be alternated 



Fig. 433. — Belladonna {Atropa Belladonna) 



1, Corolla opened. 2, Pistil. 3, Fruit. 4, Section 

 of fruit. 



