484        Recent  Literature  Relating  to  Pharmacy.     {A  October jmm 
cadmium,  as  well. as  the  usual  salts,  many  of  which  were  prepared 
and  analyzed. 
As  preliminary  in  establishing  structural  formula,  the  writer  pre- 
pared with  ethyl  iodide  a  crystalline  product  C19H22C2H5N05HI,  from 
which  the  hydriodic  acid  was  separated  by  sodium  carbonate,  addi- 
tional ethyl  groups  were  not  taken  up  showing  it  to  be  a  secondary 
amine.  Further  proof  of  this  was  shown  by  the  phenyl  thiourea 
product  CSNHC6H5  NC19H22N05,  formed  when  the  alkaloid  was 
treated  with  phenyl-mustard  oil.  The  body  gave  no  reactions  of 
aldehyde  or  ketone,  but  did  respond  to  Zeisel's  test  for  the  methoxyl 
group  (OCH3),  showing  three  such  groups.  Finally,  treatment  with 
benzoyl  chloride  yielded  a  derivative  containing  two  benzoyl  groups, 
showing  presence  of  two  hydroxyls.  This  data  indicates  as  formula 
of  lauro-tetanin  C16Hn  (OCH3)3  (OH)2  NH,  which  disproves  Gres- 
hofT's  idea  that  it  was  identical  with  berberine.  The  writer  investi- 
gated the  physiological  action  of  the  alkaloid,  which  is  as  suggested 
by  name.  H.  V.  Arny. 
ESTIMATION  OF  DENSITY  OF  POWDERS. 
M.  Vandevyver  {Ann.  d.  Chimie  Analytique,  1899,  3)  describes  an 
apparatus  for  estimation  of  specific  gravity  of  powders,  which  has 
the  advantage  of  leaving  the  substance  intact.  It  consists  of  a  flask 
of  known  weight  and  capacity,  provided  with  a  three-way  stop-cock 
and  a  manometer,  consisting  of  two  glass  tubes  connected  by  rub- 
ber tubing.  The  method  of  estimation  is  a  clever  application  of 
Mariott's  law — manometric  readings  being  taken  before  and  after 
the  weighed  powder  is  placed  in  the  flask,  and  from  data  thus  ob- 
tained an  equation  is  evolved.  Details  are  useless  unless  accompa- 
nied by  cut  of  apparatus,  hence  the  reader  is  referred  to  original  ar- 
ticle. H.  V.  A. 
PREPARATION  OF  STANDARD   SULPHURIC   ACID  SOLUTIONS. 
Arthur  Marshall,  in  the  Jour.  Soc.  Chem.  Ind.,i8t  4  (1899),  gives 
a  brief  resume  of  some  of  the  methods  proposed  for  making  such 
solutions,  and  shows  that  all  of  them  involve  a  number  of  opera- 
tions, each  of  which  is  liable  to  introduce  more  or  less  error.  He 
comes  to  the  conclusion  that  by  far  the  most  accurate  and  rapid  re- 
sults can  be  obtained  by  basing  standardizations  on  the  very  accur- 
ate densities  of  sulphuric  acid,  made  by  S.  U.  Pickering,  in  1890, 
