306  Preparation  of  Arsphenamine.  {Amuayr\g^9arm' 
Ehrlich  and  Bertheim  found  that  in  the  same  preparation  just 
mentioned  the  carbon  content  was  32.63  per  cent.  The  theory  for 
1  molecule  of  methyl  alcohol  calls  for  33.12  per  cent.  C,  while  the 
theory  for  2  molecules  of  water  requires  only  30.32  per  cent.  C. 
Qualitative  Tests. — Of  the  qualitative  tests  suggested  and  com- 
piled by  Meyer14  and  DuMez,  we  have  tried  the  following  ones  only, 
which  we  consider  the  most  important,  and  obtained  the  reactions 
described  in  every  respect : 
Dilute  sulphuric  acid  gave  an  insoluble  hydrosulphate. 
Nitric  acid  gave  the  characteristic  color. 
Preparation.                |    Per  Cent.  As. 
Per  Cent.  N. 
Per  Cent.  CI.     Per  Cent.  Sulphur. 
No.  9  
32.01 
31-86 
31.62 
31-95 
31-21 
32.32 
5.60 
5-67 
16.84 
16.75 
Average  
31-83 
5-63 
16.79 
No.  10  
31.02 
31.62 
32.11 
32.34 
31.77 
32.11 
5-64 
5-64 
14.18 
14.OO 
Average  
31.83 
5-64 
14.09 
No.  11  
30.43 
30.90 
30.25 
29-93 
5-78 
5.88 
14.72 
14.63 
Average  
30.38  5-83 
14.67 
0.30 
No.  12  
32.62 
33-07 
33-00 
33-07 
32.71 
6.30 
6-45 
14.18 
14.OO 
Average  
32.89 
6-37 
14.09 
Bromine  water  gave  the  color  described. 
Phosphotungstic  acid  gave  the  color  reaction  for  phenols. 
Silver  nitrate  gave  the  beautiful  red  colored  complex  described 
by  Danysz.15 
14  Public  Health  Reports,  33,  1004,  1918. 
15  Compt.  rend.,  157,  644,  1913 ;  ibid.,  158,  199,  1914. 
