^b/uaryjm111'}        Cocoa:  Its  Production  and  Use.  55 
calibre  at  every  part — and  by  far  the  greater  portion  is  very  far  off 
in  this  particular — it  is  no  wonder  that  it  is  only  by  accident  that  one 
happens  to  become  the  happy  possessor  of  a  first-class  instrument. 
Where  it  is  imperative  to  determine  the  temperature  with  exact- 
ness, the  only  recourse  is  to  have  the  thermometer  verified  and  use 
the  necessary  corrections  in  connection  with  it. 
My  advice  is'  to  try  the  freezing  and  boiling  points  of  every  ther- 
mometer to  be  used,  for  one  can  rest  assured  that  if  these  do  not 
register  correctly  there  is  very  little  probability  of  any  other  part 
being  of  much  value.  One  other  fact  should  not  be  overlooked  in 
selecting  a  thermometer,  namely,  the  complete  absence  of  air.  This 
can  readily  be  determined  by  inverting  the  instrument  and  giving  a 
few  taps  on  the  end,  when,  if  free  from  air,  the  mercury  will  com- 
pletely fill  the  tube  and  show  an  empty  space  in  the  bulb,  this  again 
will  disappear  when  the  instrument  is  turned  to  its  proper  position 
and  the  mercury  descends  in  the  tube  to  its  normal  place.  Besides 
these  precautions  there  is  nothing  to  indicate  a  good  thermometer 
except  a  comparison  with  one  of  known  accuracy. 
COCOA:  ITS  PRODUCTION  AND  USE. 
By  Whuam  B.  Marshai,i,. 
One  of  the  engravings  in  Dufour's  "  Treatise  on  Coffee,  Tea  and 
Cocoa/'  published  in  1688,  shows  a  Chinaman, aTurk  andan  American 
aborigine  having  a  merry  good  time  at  a  liquid  banquet — the  China- 
man with  his  tea-pot  and  tea,  the  Turk  with  his  coffee-pot  and  coffee, 
and  the  American  with  his  chocolate  urn  and  cocoa.  Another  picture 
in  the  same  work  shows  a  Turk,  an  American  and  a  Chinaman,  each 
with  a  cup  of  his  favorite  beverage.  Contentment  glows  on  the  face 
of  each,  but  the  way  in  which  the  Turk  and  Indian  regard  the  China- 
man indicates  that  they  are  thinking  or  saying,  "  Your  tea  may  be 
good,  but  what  I  have  here  is  far  better,"  and  of  the  three  the  Indian 
seems  best  pleased.  Theoretically,  cocoa  should  hold  first  rank  in 
the  field  of  table  beverages,  but  in  practice  the  order  of  rank  is  coffee 
first,  tea  second  and  cocoa  third.  They  hold  this  relative  rank  in 
the  quantity  grown  and  used,  in  the  commercial  value  and  in  the 
frequency  of  use.  All  this  is  so  notwithstanding  the  fact  that  nearly 
everybody  likes  cocoa  from  the  very  first  time  it  is  tasted,  and 
