512 
Reactions  of  Albumin. 
(Am,  Jour,  ^harm 
I  November,  1903. 
acid  no  acid  albuminate  solution  is  obtained,  nor  is  an  alkali  albumi- 
nate formed  on  dissolving  an  acid  albuminate  in  water  by  the  aid  of 
a  little  alkali.  In  the  first  case,  we  obtain  a  solution  of  the  com- 
bination of  the  alkali  albuminate  and  the  acid,  and  in  the  other 
case  a  soluble  combination  of  the  acid  albuminate  with  the  alkali 
added.  Dilute  solutions  with  alkalies  act  more  energetically  on 
proteids  than  do  acids  of  corresponding  concentration." 
The  albumins  possess  some  very  interesting  physical  features. 
If,  for  example,  we  take  the  white  of  an  egg  (the  albumins  of  which 
are  very  closely  related  to  the  albumins  of  blood  plasma,  and  its 
globulins  to  serum  globulins)  we  find  it  consists  of  a  frame-work 
of  thin  membranes  enclosing  a  yellowish  albuminous  liquid  of  light 
density.  The  viscosity  of  white  of  egg  is  due  to  its  membranes. 
Its  gravity  is  1-045,  anc*  it  is  always  alkaline  in  reaction.  Its  album- 
inous bodies  are  mixtures  of  albumins  and  globulins  together  with 
a  mucin.  The  albumins  are  soluble  in  water.  On  diluting  white 
of  egg  with  water  the  globulins  separate,  and  on  diluting  it  with 
four  volumes  of  water  the  mucin  is  precipitated.  I  have  observed, 
however,  the  interesting  fact  that  if  to  25  grammes  of  egg  white 
there  be  added  sufficient  sodium  chloride  and  water  to  make  100 
c.c.  Of  a  0  6  per  cent,  solution  of  NaCl,  the  globulins  and  mucin 
are  brought  immediately  into  solution.  If  the  solution  be  saturated 
with  sodium  chloride,  the  globulins  are  precipitated. 
The  proportion  of  6  parts  per  thousand  of  sodium  chloride  in 
water  corresponds  in  strength  with  that  of  a  physiologically  normal 
salt  solution,  and  the  valuable  therapeutic  results  following  the  injec- 
tion of  this  solution  into  the  body,  in  certain  pathological  conditions, 
is  apparently  due  to  the  fact  that  the  saline  solution  not  only  dilutes 
poisons  in  the  blood  by  increasing  the  volume  of  blood  plasma,  but 
makes  this  increase  under  normal  physical  conditions  whereby  the 
globulins  and  mucin  are  kept  in  solution,  and  not  under  abnormal 
physical  conditions,  such  as  obtain  with  the  injection  of  water  alone.1 
In  health,  the  amount  of  sodium  chloride  in  blood  plasma  is  re- 
1  On  the  ground  that  normal  salt  solution  mixed  with  blood  washes  out  the 
coloring  principle  of  the  red  corpuscles  into  the  blood  serum  (in  which  it  is 
soluble)  and  is  therefore  objectionable,  a  modified  formula  for  a  "clinical 
saline  solution  "  has  been  devised  but  is  not  generally  used,  which,  it  is  claimed, 
does  not  do  this.  It  is  as  follows  (Harvey  Gushing  in  "S.  Solis  Cohen's  Sys- 
tem of  Physiologic  Therapeutics,"  1902,  Vol.  IX,  p.  289): 
