348 
Story  of  the  Papazv. 
Am.  Jour.  Pharai. 
July,  1901. 
the  latex  than  the  product  resulting  from  any  other  method  which 
has  come  under  my  observation. 
(7)  Salt-precipitation  method.  The  well-known  methods  of 
precipitation  by  alkaline  salts  are  applicable  to  the  separation  of 
the  papaw  ferments.  The  latex  diluted  with  water  or  the  dried 
latex  extracted  with  water  (filtered),  when  saturated  with  sodium 
chloride,  with  ammonium  sulphate  or  with  magnesium  sulphate, 
will  yield  a  heavy  precipitate  of  the  proteid  contents  carrying  the 
greater  portion  of  the  ferments.  Such  precipitates  may  be  freed 
from  salts  by  subjecting  their  solution  to  dialysis,  the  resulting  solu- 
tion (and  precipitated  residue)  are  then  to  be  evaporated  to  dryness. 
The  yield  from  these  salt-precipitation  methods  is  small,  but,  if 
the  processes  are  carefully  performed,  furnish  a  satisfactory  product, 
weaker  however  in  action  than  those  prepared  by  the  method  out- 
lined in  the  preceding  section. 
Something  like  thirty  methods  for  separation  have  been  tried  in 
my  researches  with  the  result  that  all  methods  where  precipitation 
is  involved,  tend  to  weaken  the  digestive  power  of  the  ferment. 
Ihe  metrods  used  in  the  separation  of  pepsin  whereby  a  purified 
and  high  power  pepsin  is  produced,  are  as  follows:  Digestion  of 
the  proteid  constituents,  precipitation  and  purification  of  the  pro- 
duct do  not  seem  to  be  applicable  to  the  papaw. 
If  the  proteids  of  the  papaw  are  digested  by  the  aid  of  the  con- 
tained ferments  in  either  acid,  neutral  or  alkaline  fluids,  and  a 
separation  and  purification  then  made,  the  resulting  product  is  de- 
creased, and  the  digestive  power  is  not  increased  ;  in  fact,  unless 
the  process  is  most  carefully  performed,  the  absolute  power  of  the 
ferment  is  greatly  weakened. 
It  has  been  stated  that  the  ferments  of  the  papaw  are  chiefly  as- 
sociated with  one  of  its  protei  \  constituents.17 
I  have  never  been  able  to  verify  this  statement.  When  any  of 
the  various  forms  of  proteids  are  separated  by  the  processes  else- 
where outlined,  heat  or  coagulation  excepted,  the  separated  body 
will  be  found  to  possess  ferment  power.  Even  the  peptone  remain- 
ing after  separation  of  the  albumoses  exhibits  feeble  ferment  powers. 
The  ferment  action  seems  to  be  the  most  marked  when  all  of  the 
proteids  are  associated  together  in  their  natural  form. 
( To  be  continued.') 
17  Martin  believed  the  ferment  to  be  associated  with  the  proteid  which  he 
termed  B  Phytoalbumose. 
