Mr.  de  luc  on 
52s 
liquor  from  this  fixed  point  of  temperature  would  leflen 
the  effect  of  the  fpirituofity  in  the  immediate  indication 
of  the  Areometer,  comparatively  with  what  it  fhould  be 
found  at  this  determined  point. 
1 have  here  alfo  taken,  for  the  comparifon  of  the  indi- 
cation of  the  Thermometer  with  the  denfity  of  the  fame 
liquor  differently  warmed,  terms  which  are  within  the 
extremes  of  the  common  obfervations,  becaufe  here  feve- 
ral  caufes  are  combined  in  the  fame  effect.  1.  The  pro- 
greffion  of  the  dilatations  of  fpirituous  liquids  compara- 
tively to  quickfilver.  2.  The  different  progreffions  of  the 
liquids  of  different  degrees  of  fpirituofity.  3.  The  change 
of  bulk  of  the  inftrument  itfelf  in  liquors  of  different 
temperatures.  It  became  then  neceflary  to  avoid  taking 
the  fundamental  terms  of  comparifon  very  wide  of  each. 
other, 
tre;  puifque  le  refroidiffement  depuis  ce  point  fixe  de  temperature,  diminueroir 
l’effet  de  la  fpirituofite  fur  1’indication  immediate  de  l’Areometre,  comparative- 
ment  a ce  qu’on  la  trouveroit  a ce  point  determine. 
J’ai  pris  encore  ici  pour  la  comparaifon  de  l’indication  du  Thermometre  avec 
la  denfite  d’urte  meme  liqueur  differemment  chaude,  des  termes  qui  fe  trouvent 
en  dedans  des  extremes  des  obfervations  ordinaires;  parce  qu’ici  plufieurs  caufes 
fe  combinent  dans  un  meme  effet,  favoir,  i°.  La  marche  des  dilatations  des  liqueurs 
fpiritueufes  comparativement  au  mercure.  2°.  La  difference  de  marche  des  liqueurs' 
de  different  degre  de  fpirituofite.  30.  Les  changemensde  volume  de  l’infirument 
lui  meme  dans  les  liqueurs  differemment  chaudes.  II  falloit  done  eviter  de 
prendre  les  termes  fondamentaux  de  comparaifon  a une  grande  diftance,  de  peur 
de 
