DOSES AND ADMINISTRATION 485 



employed in human medicine. Crude opium is given to 

 horses and dogs made into bolus or pill, and no other solid 

 form is necessary. To reduce it to powder, it is first dried 

 in a vapour bath, and its trituration is facilitated by mixture 

 with potassium sulphate, or other hard salt. The extract, 

 containing 20 per cent, of morphine, though somewhat less 

 bulky than crude opium, is seldom prescribed. Dover's 

 powder, the pulvis ipecacuanhse compositus, consists of one 

 part each of powdered opium and ipecacuanha, and eight 

 parts potassium sulphate, added to facilitate trituration and 

 intermixture of the vegetable matters. It contains 10 per 

 cent, of opium, and is given to dogs in doses of grs. v. to 

 grs. xv. A watery solution, made by rubbing down opium 

 in hot water, and giving both dissolved matters and residue, 

 has the merit of being cheaper than the tincture, and is 

 more prompt and effectual than the solid drug. 



The B.P. tincture of opium, popularly known as laudanum, 

 is made with three ounces of opium and equal parts of 

 distilled water and alcohol (90 per cent.). It is now standar- 

 dised to contain 0*75 per cent, of anhydrous morphine. 

 An ounce contains the soluble matter of nearly 33 grains of 

 opium, or about one grain in 15 minims. For immediate 

 effects laudanum is usually preferable to solid opium. The 

 dose for horses and cattle is fgj. to fiij. ; for sheep and 

 pigs, f3ij. to f3vj. ; for dogs, TI\v. to Tl\xl. The vinegar 

 and wine of opium are seldom used in veterinary practice ; 

 but the Ammoniated tincture, known as Scotch paregoric, 

 containing one grain of opium in 96 minims is sometimes 

 given. Tinctura eamphorse composita or English paregoric, 

 made with tincture of opium, benzoic acid, camphor, oil of 

 anise, and alcohol (60 per cent.), contains J grain opium in 

 each fluid drachm. The liquid extract of opium contains 

 gr. | of morphine in 110 minims; or gr. i. of opium in 

 15 minims. Equal parts of laudanum and soap liniment 

 make an excellent anodyne, much used externally. 



Heroin (diacetyl-morphine), derived from morphine, is 

 a white crystalline powder, alkaline, odourless, with a bitter 

 taste ; soluble in acidulated water. The hydrochloride, 

 soluble in two parts of water, is sometimes employed as a 

 substitute for morphine in the treatment of respiratory 



