48 
Protoplasm  and  its  History. 
Am.  Jour.  Pharm. 
Jan.,  1S90. 
Next  comes  the  master,  Mohl.  In  1844,  in  a  paper  on  the  circulation  within 
vegetable  cells,  he  speaks  of  the  living  mass  in  each  active  cell  and  distinctly 
recognizes  it  as  that  which  is  the  treasury  of  stored  energy  and  the  vehicle  of 
energy  under  release.  He  describes  it  as  that  which  builds  shapely  forms  out 
of  unformed  matter  and  at  first  hands.    This  substance  he  names  protoplasma. 
The  term  protoplasm  was  at  once  adopted  by  Schleiden,as  a  good  substitute 
for  the  indefinite  and  misleading  word  schleim,  which  he  had  employed  to 
designate,  essentially  the  same  substance,  and  it  became  thoroughly  established 
in  scientific  terminology.  In  1850,  Prof.  Cohn  (and  linger  in  1855;,  showed  that 
the  protoplasm  of  vegetable  cells  is  identical  with  what  had  been  described,  in 
1835,  in  animal  structures  as  sarcode  by  Dujardin. 
Mohl  gives  the  following  account  of  protoplasm.  4 4  If  a  tissue  composed  of 
young  cells  be  left  some  time  in  alcohol,  or  treated  with  nitric  or  muriatic  acid, 
a  very  thin,  finely  granular  membrane  becomes  detached  from  the  inside  of 
the  walls  of  the  cells,  in  the  form  of  a  closed  vesicle,  which  becomes  more  or 
less  contracted,  and  consequently  removes  all  the  contents  of  the  cell  which  are 
enclosed  in  this  vesicle  from  the  wall  of  the  cell.  This  inner  cell  he  calls  the 
primordial  utricle.  In  the  center  of  the  young  cell,  with  rare  exceptions,  lies  the 
so-called  nucleus  cellulse  of  Robert  Brown  ('  Zcllenkern '  Cute-blast'  of  Schlei- 
den).  The  remainder  of  the  cell  is  more  or  less  densely  filled  with  an  opaquer 
viscid  fluid  of  a  white  color,  having  granules  intermingled  in  it,  which  fluid  I 
call  protoplasm." 
Hofmeister's  description  of  protoplasm,  given  in  his  Vegetable  Cell  (1867), 
is :  "  The  substance  protoplasm,  whose  peculiar  behavior  initiates  all  new  devel- 
opment, is  everywhere  an  essentially  homogeneous  body.  It  is  a  viscid  fluid 
containing  much  water,  having  parts  easily  motile,  capable  of  swelling  and 
possessing  in  a  remarkable  degree  the  properties  of  a  colloid.  It  is  a  mixture 
of  different  organic  matters,  among  which  albuminoids  and  members  of  the 
dextrin  group  are  always  present.  It  has  the  consistence  of  a  more  or  less 
thick  mucus  and  is  not  miscible  with  water  to  any  great  extent." 
From  these  accounts  we  see  that  the  following  points  were  regarded  as 
established:  (1)  All  of  the  activities  of  the  vegetable  cell  are  manifested  in  its 
protoplasmic  contents.  (2)  Protoplasm  consists  chemically  of  a  nitrogenous 
basis.  (3)  Protoplasm  has  no  demonstrable  structure.  (4)  The  protoplasmic 
contents  in  one  cell  are  not  connected  with  the  protoplasmic  contents  in 
adjoining  cells.  (5)  The  nucleus  and  other  vitalized  granules  in  the  vegetable 
cell  are  formed  by  differentiation  from  amorphous  protoplasm.  It  is  now  our 
duty  to  see  in  what  manner  these  views  have  been  modified  during  the  last 
twenty  or  rather  ten  years. 
The  first  thesis,  namely,  that  all  of  the  activities  of  the  vegetable  cell  are 
manifested  in. its  protoplasmic  contents,  may  be  regarded  as  firmly  established. 
The  second  thesis,  viz.,  protoplasm  consists  chemically  of  a  nitrogenous  basis, 
remains  unchanged.  But,  instead  of  regarding  the  protoplasmic  basis  as  com- 
paratively simple,  it  is  now  known  to  be  exceedingly  complex  and  to  contain 
numerous  cognate  proteids,  some  of  which  can  be  identified  in  the  basic  mass, 
others  in  the  nucleus,  and  others  still  in  the  vitalized  granules.  As  a  result  of 
recent  studies,  it  becomes  more  and  more  clear  that  the  chemical  relations  of 
the  protoplasmic  activities  are  still  veiled  in  mystery.  Botanists  are  now 
receding  from  the  position  that  it  is  safe  to  use  the  words  albuminoids  and 
