AnA5ust,^9oi!'m*  1        Chromic  'Acid  and  the  Chromates.  397 
decinormal  factor  of  potassium  bichromate  is  one-sixth  of  0-029378  or 
0-004896. 
An  examination  of  several  samples  of  "  chromic  acid"  gave  the 
following  results  : 
Number. 
Color  of  Crystals. 
Sulphates. 
Per  Cent,  of  Cr03. 
Aqueous  Solution. 
Brownish  red 
Much 
6666 
Clear 
2 
Dark  crimson 
None 
9571 
3 
Iyight  brick  red  j 
60-53  per  cent,  calculated 
as  NaHS04,  H20 
}  38-28 
4 
59-76  per  cent,  calculated 
as  NaHS04,  H20 
}  38-89 
5 
Crimson  j 
4'2  per  cent,  calculated 
as  H2S04 
}  93-83 
There  certainly  is  a  marked  difference  in  the  physical  appearance 
of  the  above  samples.  No.  2  was  of  satisfactory  quality.  No.  5  was 
a  beautiful  crystalline  product  and  the  writer  was  very  much  sur- 
prised to  get  a  reaction  for  sulphates.  It  also  gave  evidence  of 
containing  a  sodium  salt.  Nos.  3  and  4  were  fairly  good  physically. 
According  to  the  above  analysis  they  consisted  of  nothing  but  a 
mixture  of  chromic  acid  and  sodium  acid  sulphate,  obtained  by  mix- 
ing the  proper  proportions  of  sulphuric  acid  and  sodium  bichromate  ; 
Na2Cr207,  2  H20  +  2  H2S04  =  2  CrOs  +  2  NaHS04  +  3  H20 ; 
then  evaporating  the  mixture  to  dryness.  These  samples  may 
have  been  intended  for  technical  purposes,  but  no  such  information 
could  be  found  anywhere  on  the  container.  It  appears  to  be  the 
custom  of  some  manufacturers,  however,  to  deliver  some  of  their 
goods  without  the  semblance  of  a  label  as  to  contents  or  quality; 
which  appears  to  the  writer  to  be  a  very  dangerous  practice. 
The  above  method  has  also  been  applied  to  the  soluble  chro- 
mates with  satisfactory  results. 
Laboratory  of  Smith,  Kline  &  French  Co. 
Dr.  Charges  Mohr,  the  well-known  botanist,  died  July  17,  at  Asheville, 
N.  C.  He  was  to  be  classed  with  the  school  of  botanists  who  contributed  so 
much  to  the  development  of  American  Botany. 
Dr.  Henry  C.  C.  Maisch,  eldest  son  of  the  late  Professor  John  M.  Maisch, 
died  July  1st,  in  Philadelphia.  In  recent  years  he  had  devoted  himself  to  phar- 
maceutical chemistry  and  analytical  work. 
