594 
Capacity  of  Spoons. 
( Am.  Jour.  Pharm. 
I  December,  1901. 
half  a  fluid  ounce  (i  5  cc);  usually  it  is  almost  20  c.c."  I  have  tested 
a  number  of  spoons,  such  as  are  in  common  use,  filling  each  with 
distilled  water  to  its  full  capacity  and  then  measuring  the  amount. 
The  following  results  are  given :  No.  I  (a  small  teaspoon)  contains 
75  m. ;  No.  2,  85  m.;  No.  3,  100  m. ;  No.  4,  100  m. ;  No.  5,  1 10  m. ; 
No.  6,  no  m. ;  No.  7,  120  m. ;  No.  8,  120  m. ;  No.  9,  120  m. ;  No. 
10,  130  m.,  the  average  being  107  m.  (about  7  c.c).  As  Nos.  2  and 
3  are  each  known  to  be  100  years  old,  we  might  infer  that  there  has 
been  an  increase  in  the  size  of  teaspoons,  as  the  rest  of  them  are  of 
much  later  date.  Of  the  three  dessertspoons  shown  you  their 
capacity  is  as  follows:  No.  1  (modern),  3  fluid  drachms;  No.  2  (80 
years  old),  full  3  fluid  drachms  ;  No.  3  (50  years  old),  scant  4  fluid 
drachms.  The  six  tablespoons  shown  you  have  a  capacity  as  fol- 
lows: No.  I  (100  years  old),  4  fluid  drachms;  Nos.  2,  3  and  4 
(modern),  each  5  fluid  drachms  ;  No.  5  (60  years  old),  full  5^  fluid 
drachms;  No.  6  (modern),  6  fluid  drachms.  When  filled  with  strong 
alcoholic  tinctures,  such  as  Tinct.  Cinchona  Comp.,  they  contain 
about  10  per  cent,  less,  owing  to  the  fact  that  the  cohesion  between 
the  molecules  of  alcohol  is  less  than  that  between  the  molecules  of 
water.  Filled  with  tinctures  made  from  diluted  alcohol,  such  as 
Tinct.  Digitalis,  they  contain  about  5  per  cent,  less  than  they  do  of 
water.  Filled  with  syrup,  such  as  Syr.  Pruni  Virg.,  the  amount  is 
about  the  same  as  that  of  water,  but  about  10  per  cent,  adheres  to 
the  spoons  and  cannot  be  measured.  My  conclusions  are  as  follows, 
viz. :  In  actual  practice  few  persons  fill  spoons  perfectly  full  with 
medicinal  liquids,  but  only  approximately  so,  therefore,  by  the  use 
of  the  average  teaspoon  the  patient  would  get  about  50  per  cent, 
more  than  the  theoretical  quantity.  The  average  dessert  and  table- 
spoon would  give  about  25  per  cent.  more.  As  the  teaspoon  is  the 
measure  by  which  liquid  medicines  are  ordinarily  administered,  this 
average  increase  in  size  of  50  per  cent,  becomes  a  matter  of  some 
consequence,  especially  when  maximum  doses  of  active  drugs  are 
prescribed.  For  instance,  a  physician  might  think  he  was  giving 
the  -Ij  of  a  grain  of  strychnine,  whereas  by  the  ordinary  teaspoon 
the  patient  would  get  of  a  grain,  or  nearly  y1^.  Or  4  m.  of 
hydrocyanic  acid  might  be  prescribed  as  a  dose,  but  the  patient 
would  get  6  m.  This  disparity  between  theory  and  practice  is  par- 
tially recognized  by  some  physicians  ;  one  that  I  am  acquainted  with 
always  prescribes  a  2^ -ounce  mixture  when  he  wishes  the  patien 
