THE 
AMERICAN  JOURNAL  OF  PHARMACY. 
SEPTEMBER,  1860. 
ON  SOME  POINTS  OF  CHEMICAL  THEORY,  ON  THE  AMMONIA- 
AND  AMMONIUM-BASES,  AND  ON  THE  NATIONAL  PHARMA- 
COPOEIA ;  being  Extracts  from  the  Introductory  Lecture,  delivered 
before  the  Class  of  Jefferson  Medical  College,  of  Philadelphia,  October 
14,  1858.  Br  Franklin  Bache,  M.  D.,  Professor  of  Chemistry  in  the 
College. 
It  is  well  known  that  the  ponderable  elements  have  fixed 
combining  weights,  called  their  equivalents,  which  form  a  chain 
of  ratios,  representing  the  proportion  in  which  they  unite  with 
one  another.  This  fixedness  of  the  combining  ratios  by  no 
means  implies  that  they  shall  be  necessarily  represented  by 
whole  numbers.  In  order  that  they  may  be  whole  numbers, 
their  relation  must  be  such,  that  they  may  be  all  divided  by  the 
same  number  without  a  remainder.  Prout  contended  at  an 
early  period,  that  the  combining  numbers  were  divisible  in  this 
way  ;  in  other  words,  that  they  might  be  divided  by  some  num- 
ber forming  the  common  divisor  of  them  all.  The  number  which 
he  selected  for  the  common  divisor  was  the  combining  number 
of  hydrogen,  which  he  fixed  at  one.  Accordingly,  he  said  that 
his  common  divisor,  one,  was  contained  in  the  combining  number 
of  hydrogen  once,  in  the  combining  number  of  carbon,  six  times, 
in  the  combining  number  of  oxygen,  eight  times,  in  the  com- 
bining number  of  nitrogen,  fourteen  times,  and  so  forth.  Ber- 
zelius,  to  the  last  moment  of  his  life,  rejected  the  law  of  Prout, 
that  the  combining  numbers  are  exactly  divisible  by  a  common 
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