514 
WEIGHT  OF  A  FLUIDOUNCE  OF  WATER. 
Moreover  let  us  have  a  large  edition,  cheap  as  becomes  a  brief 
and  concise  work,  edited  without  expense,  and  let  it  be  so 
thoroughly  advertised  and  introduced,  that  it  will  cease  to  be 
as  formerly  a  curiosity  in  drug  stores  and  the  offices  of 
physicians,  not  one  of  which  can  with  propriety  be  without  it. 
ON  THE  WEIGHT  OF  A  FLUIDOUNCE  OF  WATER. 
By  Dr.  W.  H.  Pile. 
The  problem  of  reducing  weight  to  measure,  as  in  the  deter- 
mination of  the  weight  of  a  definite  bulk  of  water,  although  ap- 
parently a  very  simple  operation,  involves  processes  so  compli- 
cated and  delicate,  that  the  question  is  still  an  open  one,  not- 
withstanding the  most  acute  observers  of  modern  times  have  en- 
tered into  the  investigation  and  pursued  it  diligently  for  years. 
The  governments  of  England  and  France,  and  we  may  add  our 
own  also,  in  their  endeavors  to  have  this  fundamental  inquiry 
settled,  have  employed  the  utmost  skill  and  ingenuity  available, 
in  devising  mechanical  means  for  overcoming  difficulties ;  some 
of  these  are,  however,  in  their  very  nature  insurmountable,  and 
the  utmost  that  we  may  expect  is  a  nearer  approach  to  accuracy 
as  modern  science  devises  new  means,  and  more  refined  inves- 
tigations are  instituted. 
The  above  remarks  are  made  introductory  to  a  question  re- 
ferred to  me,  as  to  the  weight  of  a  fluidounce  of  water,  and 
the  determinations  of  various  authorities  on  this  point  are  given 
below,  collected  from  such  sources  as  I  have  been  able  to  meet 
with. 
The  United  States  (see  Alexander  on  weights  and  measures) 
define  a  gallon  of  water,  of  231  cubic  inches,  at  its  greatest 
density,  39-83°  F.,  and  Bar.  30  inches,  to  weigh  58372.1754 
troy  grains  and  the  fluidounce  456.0326  grs. 
According  to  Kopp's  table  on  the  expansion  of  water,  re- 
duced by  myself,  (see  Amer.  Jour.  Phar.  for  1860)  when  a  bulk 
of  water  is  assumed  to  weigh  1000  grs.  at  60°  F.,  a  similar  bulk 
will  weigh  at  its  greatest  density  1000-902  grs.  The  fluid 
ounce  of  the  United  States  standard  at  60°  F.  would  conse- 
quently weigh  ?56-0326  or  455-6216  grains. 
^  J  e     10U0.902  & 
In  the  Dispensatory  by  Wood  and  Bache,  the  fluidounce  is 
