AmVJe°burx877arm'}  The  Metrical  System  in  Prescriptions.  51 
word  gram  is  never  employed  in  any  formula,  unless  another  weight 
value  besides  gram  has  been  given,  as  for  instance  in  the  formula  for 
pyroleine  de  colza  (p.  549),  for  the  preparation  of  which  Huile  de  colza 
500  kit.)  Minium  250  gr.  are  directed.  If  measures  are  intended  instead 
of  weights,  they  are  always  specially  indicated,  like  in  the  formula  for 
alcoholic  hydrocyanic  acid  (p.  209)  which  reads  :  Acide  cyanhydrique 
<anhydre  1  volume,  Alcool  6  volumes.  That  the  same  rule  holds  good 
also  for  prescriptions  may  be  easily  learned  from  the  introductory 
remarks  to  the  chapter  on  potions  (pp.  741,  742),  where  the  weight  of 
the  ingredients  and  of  the  medicine  is  three  or  four  times  referred  to, 
•  as  for  instance  in  the  following  sentence:  If  a  potion  consists  only  of 
a  mixture  of  one  or  several  syrups  with  medicated  waters  or  ptisans, 
the  syrups  are  first  weighed  and  afterwards  the  water  (Lorsqu'une 
potion  ne  consiste  que  dans  un  melange  d'un  ou  plusieurs  sirops  avec 
<des  hydrolats  ou  des  hydrops,  on  phe  d'abord  les  sirops,  puis  les  eaux). 
Prof.  E.  Soubeiran  says  on  the  same  subject  in  his  "  Traite  de 
Pharmacie  "  (edit.  1847,  ^5  P*  2I9) :  Ordinarily  there  enter  into  the 
composition  of  potions  a  syrup  in  the  quantity  of  30  to  60  grams,  dis- 
tilled waters,  vegetable  infusions  in  the  quantity  of  60  to  120  grams 
(II  entre  ordinairement  dans  la  composition  des  potions  un  sirop  a  la 
dcse  de  30  a  60  grammes,  des  eaux  distilles,  des  infusions  vegetales  a 
la  dose  de  60  a  120  grammes). 
The  medical  and  pharmaceutical  literature  of  the  continent  of  Europe 
bears  abundant  evidence  that  prescriptions  and  formulas  are  always 
given  by  weight,  and  when  they  are  copied  from  English  or  American 
periodicals,  the  values  are  usually  translated  in  grams.  If  further  proof 
was  needed,  it  may  be  mentioned  that  the  posological  tables  appended 
to  the  recent  pharmacopoeias  of  continental  Europe  give  the  doses 
invariably  in  the  metric  weight,  as  they  formerly  did  in  grains,  but 
never  in  metric  measures,  as  the  following  few  quotations  from  the 
table  of  maximum  doses  of  the  German  "  Pharmacopoeia  "  will  prove  : 
Grammata  Grammata 
Pro  dosi.  Pro  die.  Pro  dosi.  Pro  die. 
Kreosotum,       .       .       .  0*05      0*2    Tinctura  Cantharidum,        .  o-5  1*5 
Liquor  Kali  arsenicosi,  .       0  4      2*0    Tinctura  Iodi,         .       .      0*3  1*2 
Oleum  Crotonis,       .       .  o-o6      0-3    Tinctura  Opii  simplex,        .  1*5  5-0 
,  "  In  giving  ol.  ricini,"  says  Dr.  Blodgett,  "nobody  estimates  the 
dose  by  its  absolute  weight  in  grains  on  the  scale."  If  this  is  intended 
to  refer  to  the  patient,  nobody  will  object ;  but  if  to  the  physician  and 
