Of this table only the ^ains, drachms and ounces should be 

 used in prescription writing. The scruple was used at one time 

 but is largely in disuse at the present time and is unnecessary. 

 Furthermore the character is not easily made, and if made care- 

 lessly or blurred may be mistaken for the drachm sign. 

 Table op Apothecaries' (or Wine) Measure 



60 Minims (TTl) = 1 fluid drachm (f.3) 



8 Fluidrachms = 1 fluidounce (f.g) 480 ms. 



16 Fluidounces = 1 pint (0.) 7680 ms. 



8 pints = 1 gallon (Oong.) 61440 ms. 



To avoid confusion in the use 'of the Apothecary and Avoirdu- 

 pois systems, the symbols, lb., §, 3, and 3 should be consistently 

 used for the apothecary and the abbreviations, lb., oz„ gr., for the 

 Avoirdupois. The abbreviation for the Troy pound is character- 

 ized by the cross line drawn through the letters, lb., and should al- 

 ways mean 12 ounces, while the Avoirdupois pound stands for six- 

 teen ounces. The symbol ,5 means an Apothecaries' ounce of 480 

 grains, while the abbreviation means an Avoirdupois ounce of 

 437.5 grains. The grain weight is the same for both systems and 

 therefore, the abbreviation gr. will cause no confusion. The grain 

 is, therefore, the unit for both systems and the term is derived 

 from the old system of weighing, which required that there should 

 be used a grain of wheat, well dried and from the middle of the 

 ear. (head). 



The character f3 represents 60 minims, and fg is necessary to 

 represent 480 minims. 



A minim of water weighs about one grain (0.95 gr.) but it 

 should be remembered that a minim is not the equivalent of a grain. 

 480 minims (1 fo) of wafer weighed at the standard temperature 

 of 25°C. (77°F.) weighed 454.6 grains. The specific gravity of 

 liquids also varies so that a pint of liquid is not necessarily a pound. 

 In writing the apothecaries' weights and measures in prescrip- 

 tions, the figures are written in the Roman system and placed after 

 the symbol, as gr..XX not 20 grs. In printed matter the small 

 letters are used, but in writing it is better to use the capital L, be- 

 cause the small letter might easily be mistaken for an i. The ones 

 should always be dotted and the last one may be written like a j ; 

 thus § iij. The fl. before the sign 3 or § is often omitted, but under 



