734 WEIGHTS AND MEASURES 



scribed for the horse. The official tinctures of aconite, 

 digitalis, nux-vomica, cantharides, and iron perchloride, and 

 a few unofficial tinctures are sufficiently concentrated to 

 require special care in their administration. 



Medicated Spirits, are solutions of volatile oils, ethers or 

 other substances in alcohol (90 per cent.). The average 

 strength is one in ten. The simple spirits are represented 

 by those of peppermint, anise, camphor (1 in 10), jumper, 

 chloroform (1 in 20) and ether. The official compound 

 spirits (nitrous ether, sal volatile, etc.) are five in number. 



Medicated wines, such as vinum antimoniale and vinum 

 ipecacuanhae, made with sherry or orange wine, are merely 

 weak tinctures. Elixirs are tinctures mixed with aromatics 

 and syrup. 



WEIGHTS AND MEASURES, IMPERIAL AND 

 METRIC 



Two systems of weights the imperial and the apothe- 

 caries' were formerly employed by medical men, veter- 

 inarians, and chemists. The avoirdupois or imperial weight 

 was used by wholesale druggists, and also by retailers 

 in buying their drugs, and usually in selling quantities 

 amounting to or exceeding an ounce. In dealing with 

 smaller quantities, and in making up prescriptions, apothe- 

 caries' weight was employed. To avoid the ambiguity 

 occurring from the use of these two systems, the framers of 

 the B.P. in 1864 abolished the apothecaries' weight, adopted 

 the avoirdupois ounce as the standard, divided it into 437' 5 

 grains, and ignored entirely drachms and scruples. But so 

 great is the inconvenience arising from the want of some 

 denomination between the grain and the ounce, that 

 medical and veterinary authorities still use the symbols 

 ) (scruple) and 3 (drachm), the former representing 20 

 and the latter 60 grains. 



APOTHECARIES' MEASURES OP WEIGHT 



1 grain, gr.j. 



1 scruple, 5j. . . =20 grains. 



1 drachm, 3j. . . ; = 3 scruples = 60 grs. 



1 ounce, j. --. . = 8 drachms = 480 



1 pound, Ib.j. . * . =12 ounces =5760 



