Am.  Jour.  Pharm. 
Dec,  1883. 
Varieties. 
I 
629 
No.  4.  An  amber-colored  oil,  sp.  gr.  0*891.  Odor  like  that  of  com- 
fnoii  spirit  of  tar  (ol.  picis  rect.).  On  the  water  bath  a  small  quantity 
was  vaporized  within  ten  minutes,  leaving  a  mere  trace  of  resinous 
tnatter  destitute  of  betulin  odor. 
Owing  to  my  portion  of  Mr.  Greenish's  sample  being  extremely 
small,  I  have  only  been  able  to  take  its  sp.  gr.  roughly  and  found  it 
to  be  0'943  ;  this,  however,  requires  verification.  On  the  water  bath 
it  leaves  a  thick  and  tenacious  black  residue  having  the  betulin  odor. 
The  only  specimen  which  compares  favorably  with  it  is  No.  1,  which 
answers  the  description  of  the  re-distilled  oil  of  the  Dutch  Society. 
It  is  much  thinner  than  the  geiiuine  oil,  and  the  pyroligneous  odor  is 
stronger  ;  but  a  trace  of  it,  treated  as  directed  by  Mr.  Holmes,  gives  a 
powerful  betulin  odor  in  the  course  of  fifteen  minutes.  This  variety 
is  readily  obtainable.  From  the  behavior  of  No.  2  I  am  inclined  to 
think  that  it  is  a  "  made-up  "  oil,  since  the  fragrance  entirely  disap- 
pears on  the  water  bath.  No.  4  is  the  "ol.  rusci "  which  has  been  so 
largely  supplied  to  pharmacists,  and  several  eminent  dermatologists 
have  formed  their  opinions  of  the  value  of  the  remedy  from  their  expe- 
rience with  this  variety.  It  is  not  surprising,  therefore,  that  they  have 
reverted  in  some  cases  to  old-fashioned  remedies  such  as  huile  de  cade. 
This  is  to  be  regretted,  for  ol.  rusci  has  been  found  useful  in  the  hands 
of  continental  practitioners,  and  if  a  demand  were  here  made  for  the 
genuine  oil,  means  would  not  be  wanting  for  obtaining  it. 
I  cannot  conclude  without  expressing  my  thanks  to  Mr.  Holmes  for 
his  assistance,  and  to  Messrs.  Crowden  and  Hill  for  specimens. — Phar. 
Jour,  and  Trans.,  Nov.  17,  1883. 
VARIETIES. 
The  New  Hypnotic,  Paealdehyd.— This  agent  promises  to  be  an 
important  addition  to  our  resources  for  producing  sleep.  Paraldehj^d  is  a 
polymeric  modification  of  aldehyd,  and  is  expressed  by  the  formula 
C6H12O3.  It  is  colorless  ;  in  odor  resembling  chloroform,  with  a  sharp  taste. 
It  is  administered  in  doses  of  2-6  gm.,  preferably  in  a  sweetened  ten  per 
cent,  solution.  Its  immediate  effect  is  to  produce  a  perfectly  natural  sleep 
of  two  to  six  hours  duration,  from  which  the  subject  awakes  without  any 
sense  of  distress,  headache,  dullness,  or  nausea.  Its  signal  advantage  over 
chloral  hydrate  is  that  it  does  not  weaken  the  heart's  action,  nor  impede 
the  respiration  or  circulation  in  any  degree  ;  nor  does  it  establish  the  neces- 
sity for  its  continued  use,  thus  forming  a  "  habit." 
The  sole  objection  to  paraldehyd  seems  to  be  that  it  gives  an  unpleasant 
