134  Varieties.  {Amj/a 
VARIETIES. 
The  specific  gravity  and  strength  of  dialyzed  iron  has  been  determined  by 
Mr.  E.  B.  Shuttleworth  with  the  following  results : 
Pulverulent 
Well  dried  on 
Exposed  during 
Sp.  gr. 
on  water-bath. 
water-bath. 
one  night. 
Calcined. 
1*046 
5-6 
5-0  per  cent. 
I  "040 
5*5 
5'° 
6-o 
1-038 
5-2 
4' 7 
5-6 
4*3 
1-034 
5*0 
4' 3 
Taking  into  account  the  liability  of  strong  and  well  dialyzed  solutions  to  become 
gelatinous,  I  think  a  liquor  of  1*040,  yielding,  when  evaporated  and  well  dried  over 
a  water-bath,  5  per  cent,  of  residue,  best  fitted  for  medicinal  use.  Such  a  solution' 
keeps  well  j  it  can  be  readily  estimated  by  the  pharmacist — a  simple  evaporating 
dish  being  all  that  is  required — and,  moreover,  the  strength  corresponds  as  nearly  as 
possible  with  that  of  the  ordinary  tincture  of  perchloride  of  iron. 
A  word  in  regard  to  the  asserted  tastelessness  of  dialyzed  iron.  I  have  now  on 
hand  a  solution  which  has  been  dialyzing  for  42  days,  and  is  quite  gelatinous }  it 
cannot,  however,  be  strictly  described  as  tasteless.  Though  it  is  not  in  the  least 
ferruginous,  it  is  slightly  styptic,  and  produces,  when  applied  to  the  tongue,  an 
effect  similar  to  that  of  astringents.  This  is,  I  think,  to  be  attributed  to  the  pre- 
cipitation of  oxide,  which  occurs  the  moment  the  solution  comes  in  contact  with 
the  saliva,  thus  giving  rise  to  the  sensation  alluded  to. 
Provided,  then,  that  a  solution  is  deprived  of  ferruginous  taste  5  that  it  is  not 
distinctly  blackened  by  infusion  or  tincture  of  galls,  and  does  not  give  direct  evidence 
of  containing  hydrochloric  acid,  I  think  the  test  of  specific  gravity  may  be,  for 
common  purposes,  relied  on. —  Canad.  Phar.  Jour.,  Dec,  1877. 
Test  for  Elaterin.  By  David  Lindo. — The  active  principle  in  elaterium  affords 
a  very  beautiful  reaction  with  carbolic  acid  and  concentrated  sulphuric  acid.  The 
test  may  be  applied  as  follows  : 
Place  a  few  crystals  of  elaterin  in  a  small  porcelain  capsule,  and  add  one  or  two- 
drops  of  liquefied  crystals  of  carbolic  acid  (Calvert's  No.  1,  liquefied  by  moisture)* 
The  elaterin  dissolves  in  the  carbolic  acid  without  production  of  color,  but  if  two 
or  three  drops  of  concentrated  sulphuric  acid  are  allowed  to  flow  into  the  mixture, 
an  intense  and  beautiful  carmine  color  is  developed,  changing  at  first  to  orange  and 
after  some  time  to  scarlet.  Alkalies  discharge  the  color.  I  have  not  been  able  to 
obtain  a  reaction  resembling  this  with  any  of  the  alkaloids  and  carbolic  acid,  nor 
with  any  other  substance  tried.1 
If  liquefied  crystals  of  carbolic  acid  are  not  at  hand,  the  solid  crystals  can  be  used. 
After  adding  them  to  the  elaterin  add  a  drop  of  chloroform  or  alcohol  before  apply- 
1  If  a  nitrate  in  the  dry  state  is  treated  in  the  same  way  with  carbolic  and  sulphuric  acids  a  deep  greeifc 
color  is  developed,  which  changes  to  red  on  the  addition  of  a  little  water. 
