506  Chemistry  of  Tartaric  and  Citric  Acid.  {^'^oc^'il^z''^' 
distinctions  of  pharmaceutical  purity  to  be  attentively  regarded  by 
every  class  of  dealers.  With  such  a  demand  the  manufacturer  is 
admonished  that  he  may  make  expenditures  needful  for  standard 
products. 
CONTRIBUTIONS  TO  THE  CHEMISTRY  OF  TARTARIC 
AND  CITRIC  ACID. 
By  the  late  Beaumont  J.  Grosjean, 
Chemist  to  Sir  J.  B.  Lawes^  Citric  and  Tartaric  Acid  Factory^  Millwall : 
compiled  from  the  Author^  s  Manuscripts  by  R.  Warington. 
A  word  of  preface  is  perhaps  necessary.  Mr.  Grosjean  was  asso- 
ciated with  myself  for  five  years,  1870-75,  in  the  Laboratory,  at 
Millwall,  and  he  remained  there  as  sole  chemist  from  Midsummer, 
1875,  till  his  death  on  June  11th,  1882.  During  this  time  he  con- 
ducted with  great  care  many  investigations,  both  on  methods  of  ana- 
lysis and  on  processes  of  manufacture.  A  paper  ^'  On  the  Determina- 
tion of  Tartaric  Acid  in  Lees  and  Inferior  Argol,  with  some  Remarks 
on  Filtration  and  Precipitation,''  was  communicated  by  him  to  the 
Society  in  April,  1879.  The  greater  portion  of  his  results  remained 
unpublished ;  they  were,  however,  for  the  most  part  fairly  written  out 
in  the  form  of  Reports.  From  these  Reports,  from  letters,  and  from 
the  Laboratory  Note-books,  I  have,  with  the  consent  of  Sir  J.  B. 
Lawes,  prepared  the  following  abstract  of  a  portion  of  his  results : 
Different  Rate  of  Loss  of  Different  Specimens  of  Citric  Acid  in 
Dry  Air. 
In  my  own  earlier  experiments  (^^  Chem.  Soc.  J.,"  1875,  928)  the 
different  behavior  of  different  samples  of  powdered  citric  acid  had 
already  been  noticed.  In  some  cases  the  crystallized  citric  acid  lost 
the  whole  of  its  water  when  placed  over  oil  of  vitriol  for  4-6  days ; 
in  other  cases  nothing  was  lost  in  five  days.  Mr.  Grosjean  afterwards 
met  with  similar  results.  In  one  instance  he  was  fortunate  in  com- 
mencing on  the  same  day  determinations  of  water  in  three  specimens 
of  citric  acid,  which,  as  the  experiment  progressed,  proved  to  be  of 
different  characters.  Specimen  A  was  a  fine  crystal  obtained  from 
Mr.  D.  Howard.  Specimen  B  was  a  part  of  fine  crystals  made  at 
Millwall.  Specimen  C  had  been  obtained  by  recrystallizing  B  in  the 
laboratory.  All  the  crystals  were  freed  from  any  adhering  moisture 
with  blotting-paper,  and  then  powdered.    Of  A,  3  grams,  and  of  B 
