'^'oioTi,i9iY."''}<^'^^'^  Mei^'iod  for  Testing  Digitalis,  Etc.  483 
amount  of  ouabain  actually  used  to  complete  the  experiment,  and 
the  theoretical  amount  necessary  to  kill  the  animal  in  the  absence 
of  the  digitalis  body,  represents  the  amount  of  ouabain  to  which  the 
digitalis  body  used  is  equivalent.  The  amount  of  digitalis  body 
equivalent  to  .0001  Gm.  or  one  "  cat  unit,"  is  then  calculated. 
Example  to  Show  Method  of  Calculation. 
Digitalis  solution  =  i  :  100  i  c.c.  =  .010  Gm. 
Ouabain  solution  =  i :  100,000  i  c.c.  =  .000,01  Gm. 
Cat  weighing  3.21  Kgms.  received  - 
30.2  c.c.  digitalis  sol.  (.302  Gm.  drug)  or, 
.0940  Gm.  drug  per  Kgm.  body  weight ; 
5.5  c.c.  ouabain  sol.  (.000,055  Gm. 
ouabain)  or,  .000,017  Gm.  ouabain  per 
Kgm.  of  cat. 
The  difference  between  .000,017  Gm.,  the  amount  of  ouabain 
(per  Kgm.)  actually  used  to  complete  the  experiment,  and  .000,100 
G,m.,  the  theoretical  amount,  or  one  "  cat  unit,"  which  would  have 
been  required  in  the  absence  of  the  digitalis  body,  is  .000,083  Gm. 
.094  Gm.  of  the  digitalis  is  therefore  equivalent  to  .000,083  Gm. 
ouabain,  or  .094  Gm.  of  the  digitalis  =  83  per  cent,  of  one  "  cat 
unit." 
.113  Gm.  of  the  digitalis  would  then  be  equivalent  to  one  ''cat 
unit." 
F.  E.  Digitalis. 
No.  405467. 
Digitalis  dilution  i:ioo 
Ouabain  dilution  1:100,000 
.  Cat  Wt.  in     c.c.  Dig.    c.c.  Oua-  ^3,'^^^;^"  Time  in 
No.  Kgms.        Sol.       bain  Sol.  cS'Unit 
2-27-11    I         Female  3.21 
2-27-11    2        Male  2.88 
2-27-11    3        Male  2.87 
F.  E.  Digital 
No.  416233. 
5-8-11    I  Male  2.33 
5-  8-1 1    2  Female  2.18 
5-  9-1 1    3  Male  2.07 
5-  9- II    4  Female  T.83 
5-10-I1    5  Male  2.21 
5-10-11    6  Male  2.40 
30.2 
5-5 
•113,5 
95 
25.0 
3.0 
.096,8 
61 
25.0 
7.0 
.115,2 
100 
IS. 
14.0 
5.2 
•077,3 
66 
12.0 
3.6 
.065,8 
65 
II.O 
4.6 
.068,2 
80 
lO.O 
6.7 
.086,1 
73 
II. I 
6.0 
.068,8 
97 
14.0 
8.0 
.087,4 
82 
