520 
Henry  N.  Rittenhouse. 
(Am.  Jour.  Pharm. 
\  November,  1905. 
Hydrargyri  cinereum,  lanolin  being  employed  instead  of  oleate  of 
mercury. 
Unguentum  Zinci  Stearatis  is  also  official,  it  consists  of  equal 
weights  of  zinc  stearate  and  white  petrolatum. 
Zinci  Phenolsulphonas ,  Zinc  Phenolsulphonate  (Zn  (C6H504S)2). — 
This  salt  has  long  been  used  under  the  name  of  zinc  sulphocarbo- 
jate,  and  is  official  in  the  British  Pharmacopoeia  under  that  name. 
It  should  contain,  in  uneffloresced  crystals,  not  less  than  99-5  per 
cent,  of  pure  zinc  paraphenol  sulphonate  (C6H4  (OH)  SOs)2  Zn  -j- 
8H20.  No  method  for  its  preparation  is  given.  The  British 
Pharmacopoeia  directs  it  to  be  prepared  by  heating  a  mixture  of 
phenol  and  sulphuric  acid,  and  saturating  the  product  with  oxide  of 
zinc,  evaporating  and  crystallizing.  This  is  a  useful  and  welcome 
addition  to  the  United  States  Pharmacopoeia. 
Five  tests  for  identity  are  described.  The  impurities,  arsenic, 
cadmium,  lead  and  copper,  are  detected  by  means  of  the  Time-limit 
Test,  sulphate  and  chloride  in  the  usual  manner,  and  arsenic  by 
the  modified  Gutzeit's  Test. 
Zinci  Steatas,  Tajxc  Stearate. — This  salt  contains  a  small  but  vary- 
ing proportion  of  zinc  palmitate  ;  no  chemical  formula  is  given,  and 
no  directions  for  its  preparation.  This  salt  is  extensively  used  as  a 
dusting  powder.  It  enters  into  the  newly  official  unguentum  zinci 
stearatis. 
[To  be  continued. ,] 
HENRY  N.  RITTENHOUSE.1 
By  Helen  M.  Lawrence. 
Henry  Norman  Rittenhouse  was  born  December  31,  1 831,  at  the 
southeast  corner  of  Crown  and  Vine  Streets,  Philadelphia,  then  a 
residential  section  of  the  city.  He  was  the  only  child  of  Henry  and 
Eliza  Norman  Rittenhouse,  and  a  descendant  of  David  Rittenhouse, 
the  astronomer.  His  father  was  a  carpenter  and  builder  of  promi- 
nence, and  was  identified  with  numerous  important  operations  of  the 
day,  among  which  may  be  mentioned  a  portion  of  the  Girard  estate. 
1  It  may  be  of  interest  to  our  readers  to  know  that  the  writer  of  the  above 
sketch  of  Mr.  Rittenhouse,  Mrs.  Helen  M.  Lawrence,  is  his  daughter.  Mr. 
Rittenhouse  is  also  survived  by  a  widow  and  one  son,  David  Smith  Rittenhouse, 
of  Philadelphia. — Editor. 
