212  Urethanes  of  Thymol  and  Carvacrol.    |Al^r°cuhr;  f9h2frm- 
tives  have  been  considered  derivatives  of  the  oxime  and  nitroso 
types  respectively  and  may  be  illustrated  thus : 
Inhaling  the  powder  of  these  substances  effects  the  mucous 
membrane  of  the  nose  and  readily  causes  sneezing.  They  are  de- 
composed by  carbon  dioxide  in  aqueous  solution.  The  solutions  of 
the  nitroso  derivatives  in  the  hydrocarbons  heptane  and  benzene 
were  treated  with  sodium  and  heated  for  hours  in  the  water  bath, 
but  the  action  was  very  slight.  No  perceptible  evolution  of  hydrogen 
took  place  and  with  the  the  thymol  derivative  the  sodium  retained 
its  metallic  luster  for  weeks  in  contact  with  the  solution. 
The  silver  derivative  of  nitrosocarvacrol  was  prepared  by  the 
action  of  silver  nitrate  solution  on  an  equivalent  of  the  oxime  dis- 
solved in  the  theoretical  quantity  of  2N  potassium  hydroxide.  A 
greenish-brown  mush  formed,  later  turning  to  olive  and  finally 
brown.  Brandel 22a  prepared  this  compound  in  a  similar  manner,  but 
observed  the  reverse  color  changes  from  brown  to  green.  The  pre- 
cipitate was  granular  and  washed  readily  at  the  pump,  after  which 
it  was  dried  in  the  air.  It  is  a  brown  powder,  stable  in  the  air.  It  is 
slightly  soluble  in  water  and  imparts  a  reddish  color  after  boiling. 
During  heating  an  odor  is  apparent  and  it  melts  together  in  the 
hot  water.  The  yield  was  about  90  per  cent,  of  the  theoretical  by 
weight.  It  was  analyzed  for  silver  by  ignition,  after  drying  in  a 
vacuum  desiccator.  It  melts  on  heating  and  gives  a  red-brown  subli- 
mate. 
I.  0.4048  gm.  gave  0.2485  gm.  silver. 
Found  Theory  for  C10H12NO2Ag 
Silver  36.64  p.'  c.  37.72  p.  c. 
Brandel  obtained  values  for  silver  of  36.66  and  36.84  per  cent., 
but  assigns  the  formla  Ci0H12NOAg  (no  doubt  unintentional), 
which  requires  39.95  per  cent,  of  silver.  In  addition  he  observed  a 
considerable  solubility  of  the  silver  salt  in  cold  distilled  water  and 
separated  a  precipitate  containing  54.36  and  54.1  per  cent,  of  silver. 
He  assigns  to  it  the  formula  Ci0H11NOAg2,  whereas  the  silver  con- 
tent required  for  C10H\iNOAg2  is  54.91  per  cent.  No  such  com- 
bination was  observed,  however,  in  this  work. 
The  silver  derivative  of  nitrosothymol  has  been  prepared  by 
Goldschmidt  and  Schmid.22b  It  was  prepared  in  the  same  manner  as 
22aKremers  and  Brandel,  Pharm.i  Rev.,  22  (1904),  p.  250. 
22b  Goldschmidt  and  Schmid,  Ber.,  17  (1884),  p. ■  2062. 
