172  Chemistry  of  the  Proteins. 
Am.  Jonr.  Pharm 
April,  1907. 
For  instance,  a  polypeptide  containing  the  residues  of  fourteen 
amino  acids  (leucyl-triglycyl-leucyl-octaglycyl-  glycin)  when  dissolved 
in  alkalies  froths  like  a  solution  of  soap  ;  it  forms  very  insoluble 
salts  with  mineral  acids  and  gives  a  beautiful  biuret  reaction.  But 
it  does  not  follow  that  these  synthetic  products  need  be  identical 
with  any  natural  proteins,  for,  though  similar  in  the  structure  of 
their  molecules,  yet  the  kind,  number,  and  arrangement  of  the  amino 
acid  residues  may  be  quite  different.  It  will  only  be  possible  to  say 
that  a  natural  protein  has  been  synthesized  when  it  has  been  defi- 
nitely characterized  as  a  chemical  individual  and  proved  to  be  iden- 
tical with  a  synthetic  product.  This  must  be  the  trend  of  future 
work ;  peptones  and  albumoses  must  be  separated  and  characterized, 
and  still  more  complicated  peptides  built  up  from  them.  To  attain 
this  end  means  much  laborious  work,  but  the  author  has  no  doubt 
that  success  is  possible.  No  commercial  value  is  at  present  attached 
to  the  investigation  as  in  the  cases  of  organic  s)/ntheses,  which  have 
given  to  the  world  dye-stuffs,  perfumes,  synthetic  remedies  and  ex- 
plosives ;  the  investigation  of  the  proteins  has  at  present  the  purely 
scientific  aim  of  giving  to  biology  a  clearer  insight  into  the  chemical 
processes  of  animal  and  plant  life. 
THE  PROTEINS  AND  ENZYMES. 
The  proteins  are  the  material  from  which  the  organism  builds  up 
its  most  powerful  agents,  for  as  such  the  ferments  or  enzymes  may 
be  described  without  exaggeration.  These  can  produce  the  most 
varied  changes,  such  as  oxidation,  reduction,  hydrolysis,  and  con- 
densation, classical  examples  being  found  in  the  digestion  of  food 
in  the  stomach  and  intestines  or  in  the  preparation  of  alcoholic 
beverages  from  juices  containing  sug-ar  by  the  action  of  yeast.  The 
chemical  investigation  of  the  enzymes  is  still  in  its  infancy ;  all 
attempts  to  decide  their  composition  and  structure  have  so  far 
proved  in  vain  ;  but  it  is  known  with  certainty  that  they  possess 
many  resemblances  to  the  proteins  and  are  very  probably  formed 
from  them.  The  fuller  investigation  of  the  proteins  must  therefore 
throw  further  light  on  the  nature  of  the  ferments,  and  the  attempted 
synthesis  of  the  latter  from  natural  or  synthetic  proteins  would  not, 
even  at  the  present  time,  be  a  rash  enterprise.  On  account  of  the 
part  which  they  play  in  the  chemical  processes  of  the  living  organ- 
ism, ferments  and  proteins  are  so  closely  connected  that  their  inves- 
