Am6-ct0ober!?9™:  >    Specificity  of  Drugs  for  Phosphatids.  439 
Table  III. 
Brain  Lecithin,  0.2  Per  Cent. 
CaCU  to  ppt. 
Control. 
Diff.  in  CaCl2. 
1/1000  strophanthin  
.0040 
.0037 
+  -0003 
chloral  hydrate  
.0042 
.0037 
4-  -0005 
.0044 
.OO40 
+  .0004 
.0040 
.0040 
.0 
.0040 
.OO4O 
.0 
.OO37 
.0037 
.0 
.0040 
.0037 
4-  -0003 
.0040 
.OO4O 
.0 
.0036 
.0035 
4-  .0001 
atropine   
.OO50 
.0040 
+  .0010 
It  will  be  evident  from  Tables  I  and  II  that  such  heart  drugs  as 
digitalis  and  strophanthin,  etc.,  do  produce  an  effect  on  heart  lecithin 
that  brain  drugs  like  caffein  do  not.  But  in  Table  III  it  will  be 
noted  that  heart  drugs  produce  practically  the  same  effects  on  brain 
lecithin.  Therefore  it  seems  reasonable  to  suppose  that  strophanthin 
and  digitalis  are  active  on  phosphatids  because  of  the  chemical 
nature  of  the  drugs.  Very  likely  this  action  can  be  attributed  to 
the  fact  that  they  are  glucosides,  because  chemical  substances  such 
as  phlorhizin  and  saponin,  which  are  not  heart  drugs,  produce  very 
similar  results  with  both  brain  and  heart  lecithins. 
At  first  one  might  conclude  that  the  lecithins  are  in  no  way  re- 
lated to  drug  action.  But  in  the  cases  where  an  effect  on  the  pre- 
cipitation limits  of  CaCl2  is  produced  by  a  drug  it  seems  necessary 
to  assume  that  the  lipins  have  at  least  a  secondary  importance.  The 
results  would  indicate  that  the  combination  between  the  drugs  and 
the  lecithin  is  not  the  chief  cause  of  the  specific  action.  It  is  pos- 
sible that  the  effect  is  largely  oxidation,  as  noted  above.  But 
another  possible  way  of  explaining  the  relationship  is  to  suppose 
that  the  location  and  quantity  of  the  phosphatid  determine  whether 
the  particular  drug  will  enter  the  tissue  cell  or  determine  the  amount 
that  will  enter.  In  this  case  the  final  drug  effect  would  be  deter- 
mined by  the  non-phosphatid  constituents  or  the  associated  com- 
plexes of  the  interior  of  the  cell.  Strychnine  does  give  evidence  of 
direct  specificity  for  which  it  is  difficult  to  account.  • 
Different  Salts  of  Drugs. — The  following  table  records  the  dif- 
ferences in  the  precipitation  limits  found  in  the  various  salts  of 
strychnine. 
