OPIUM AND MORPHINE 267 



niacal liquid, after the precipitation of morphine. The residue is added to water, 

 precipitated by potassium hydrate, and redissolved in ether, from which codeine 

 crystallizes out on evaporation. 



Properties. — Colorless, transparent, rhombic prisms, or a crystalline powder; 

 odorless, and having a faintly bitter taste; slightly efflorescent in warm air. Solu- 

 ble in 120 parts of water, 2 parts of alcohol, 18 parts of ether, and 0.5 part of 

 chloroform at 25° C. Codeine sulphate commonly used. 



Dose.~D., gr.%-ii, (.015-.12). 



Hekoin. (Diacetylmorphine.) (Non-official.) 



This remedy, derived from morphine, was first introduced by Dreser, in 1898, 

 and is used extensively in human medicine as a substitute for morphine and 

 codeine. Heroin occurs as a white, odorless, crystalline powder, possessing a 

 slightly bitter taste and alkaline reaction. Practically insoluble in water, but 

 readily soluble in weak acidulous solutions. 



Heroin hydrochloride is a, white, crystalline, odorless powder, soluble in 2 

 parts of water. Experiments by Heinz show heroin to be 30 times more de- 

 pressing to the respiration than codeine, and 5 times more depressing than mor- 

 phine (also S" times as toxic as morphine in dogs), while it also has a depressing 

 effect upon the circulation (Hale). Whether it is superior to codeine in relieving 

 cough is a question. Tlie drug acts as a general motor depressant, hypnotic and 

 analgesic, but is not comparable to morphine in these respects. The after-effects 

 of small medicinal doses (nausea, constipation, etc.) are slight. Heroin is em- 

 ployed in the treatment of all varieties of cough affecting the human subject, 

 and in canine practice. Codeine is preferable in the author's experience. 



Heroin may be administered in powder, pill or tablet, the hydrochloride in 

 solution, every few hours. 



The dose of either is, for the dog, gr. 1/24-1/6 (.0025-.01) ; horse, gr.ss-ii, 

 (.03-.12). 



Opium and Morphine. 



The action of morphine and opium is practically the same, with 

 some exceptions to be noted. 



Action External.- — Opium may be absorbed to a slight extent from 

 the unbroken skin, and causes a mild, anodyne action. Absorption read- 

 ily occurs from mucous membranes and raw surfaces, with resulting 

 characteristic effects. 



Action Internal. — Digestive Tract.-^Opium diminishes the two 

 principal activities of the digestive organs, namely, secretion and motion. 

 Thus in dogs and cats under morphine the X-ray shows retention of 

 food in the stomach for 8 to 24< hours owing to pyloric spasm. On the 

 other hand, large doses of morphine subcutaneously cause immediate vom- 

 iting in dogs and cats. Secretions all over the body are decreased, except 

 that pi sweat. The action upon the alimentary tract in lessening secre- 

 tioUj is partly a local one and partly constitutional, following the absorp- 

 tion of the drug. The mouth is made dry, thirst is increased and appe- 

 tite impaired. Opium is absorbed rather slowly from the stomach and 

 bowels, and causes delay in the passage of ingesta, especially in the jeju- 

 num, and therefore constipation. Constipation is such a marked effect of 

 opium that it is called the "bowel splint". This action is partly due to 

 retention^ and more complete digestion in the stomach, but mainly to local 

 depression of nerve centres (Auerbach's plexus) in the intestinal walls 

 by opium, as the effect is same when the bowel is separated from the cen- 

 tral nervous system. 



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