84 
VARIETIES. 
secret  pass  into  the  public  domain.  The  following  details  are  sufficient 
to  enable  any  anatomist  to  avail  himself  of  this  important  discovery. 
The  process  of  Dr.  Burnetti,  which  he  explained,  comprises  several 
operations,  viz.  :  1 — the  washing  of  the  piece  to  be  preserved  ;  2 — the 
degraissage,  or  eating  away  of  the  fatty  matter;  3 — the  tanning;  4 — the 
desiccation. 
1.  To  wash  the  piece,  M.  Burnetti  passes  a  current  of  pure  watei 
through  the  blood-vessels  and  various  excretory  canals,  and  then  he 
washes  the  water  out  by  a  current  of  alcohol. 
2.  For  destroying  the  fat,  he  follows  the  alcohol  with  ether,  which  he 
pushes,  of  course,  through  the  same  blood-vessel  and  excretory  ducts  ; 
this  part  of  the  operation  lasts  some  hours.  The  eth*er  penetrates  the 
interstices  of  the  flesh,  and  dissolves  all  the  fat.  The  piece,  at  this 
point  of  the  process,  may  be  preserved  any  length  of  time  desired,  plunged 
in  ether,  before  proceeding  to  the  final  operation. 
3.  For  the  tanning  process,  M.  Burnetti  dissolves  tannin  in  boiling 
distilled  water,  and  then,  after  washing  the  ether  out  of  the  vessel  with 
distilled  water,  he  throws  this  solution  in. 
4.  For  the  drying  process,  Dr.  Burnetti  places  the  pieces  in  a  vase 
with  a  double  bottom,  filled  with  boiling  water,  and  he  fills  the  place  of 
the  preceding  liquids  with  warm,  dry  air.  By  the  aid  of  a  reservoir,  in 
which  air  is  compressed  to  about  two  atmospheres,  and  which  commuui- 
cates  by  a  stop- cock  and  a  system  of  tubes,  first  to  a  vase  containing 
chloride  of  calcium,  then  with  another  heated,  then  with  the  vessels  and 
excretory  ducts  of  the  anatomical  piece  in  course  of  preparation,  he 
establishes  a  gaseous  current  which  expels  in  a  very  little  time  all  the 
fluids.    The  operation  is  now  finished. 
The  piece  remains  supple,  light,  preserves  its  size,  its  normal  relations, 
its  solid  histological  elements,  for  there  are  no  longer  any  fluids  in  it.  It 
may  be  handled  without  fear,  and  will  last  indefinitely.  The  discovery  is 
a  magnificent  one,  and  the  sooner  medical  schools  are  provided  with  full 
cabinets  of  natural  and  pathological  pieces,  the  better. — St.  Louis  Med. 
Eep.,  Nov.  1,  1867,/rom  N.  Y.  Times. 
Colorless  Varnish  with  Copal. — To  prepare  this  varnish  the  copal  must 
be  picked  :  each  piece  is  broken  and  a  drop  of  rosemary  oil  poured  on  it. 
Those  pieces  which,  on  contact  with  the  oil,  become  soft,  are  the  ones 
used.  The  pieces  being  selected,  they  are  ground  and  passed  through  a 
sieve,  being  reduced  to  a  fine  powder.  It  is  then  placed  in  a  glass,  and  a 
corresponding  volume  of  rosemary  oil  poured  over  it ;  the  mixture  is  then 
stirred  for  a  few  minutes  until  it  is  transformed  into  a  thick  liquor.  It  is 
then  left  to  rest  for  two  hours,  when  a  few  drops  of  rectified  alcohol  is 
added  and  intimately  mixed.  Repeat  the  operation  until  the  varnish  is  of 
a  sufficient  consistency  ;  leave  to  rest  for  a  few  days,  and  decant  the  clear. 
This  varnish  can  be  applied  to  wood  and  metals.—  Jour.  Applied.  Chem. 
