Am.  Jour.  Phariu.  \ 
October,  1909.  j 
Assay  of  Heart  Tonics. 
4^5 
16.  Instead  of  stating  the  full  number  of  heart  tonic  units  in  all 
cases,  round  numbers  can  be  used,  which  do  not  vary  more  than  a 
given  per  cent,  from  the  actual  number  of  units.  Reference  to 
Table  II  shows  what  may  be  accomplished. 
In  actual  practice  a  table  can  be  constructed  similar  to  the  above 
for  all  the  values  that  will  be  derived  in  the  testing  of  the  heart 
tonics  under  all  conditions.  These  may  be  printed  on  a  sheet  or 
sheets  of  paper  and  kept  for  reference  in  a  book  form  or  placed  on 
TABLE  II. 
M.  F.  D.  =  normal  minimum  fatal  dose  per  Gm.  body  weight  of  Frog. 
U.s  = 
heart  tonic  units. 
Exact  No. 
Approximate  No. 
Per  cent. 
M.  F.  D.               H.  T.  U.s  inlCc. 
H.  T.  U.  s  in  1  Cc. 
Error. 
.0001 
1000 
1000 
0 
.0002 
500 
500 
0 
.0003 
333 
330 
I. 
.0004 
^50 
250 
0 
.0005 
200 
200 
0 
.0006 
166 
l60 
4- 
.0007 
142 
I40 
2. 
.0008 
125 
125 
0 
.0009 
in 
I  10 
■9 
.0010 
100 
IOO 
0 
.0011 
9i 
91 
0 
.0012 
83 
80 
3- 
.0013 
77 
77 
0 
.0014 
7i 
70 
1. 
.00 1 5 
66 
66 
0 
.0016 
62 
62 
0 
.0017 
59 
59 
0 
.0018 
55 
55 
0 
.0019 
53 
53 
0 
.0020 
50 
50 
0 
.0100 
10 
10 
0 
a  chart  to  hang  on  the  wall  of  the  operation  room  and  used  in  the 
same  manner  as  interest  or  logarithm  tables.  Such  practice  would 
obviate  entirely  the  necessity  for  the  person  doing  the  testing  to 
make  mathematical  computations  unless  a  correction  would  be 
needed,  in  order  to  convert  an  abnormal  minimum  fatal  dose  of 
standard  into  H.T.U.s  as  stated  below.  These  variations  can  also 
be  worked  out  and  converted  into  tables. 
17.  A  correction  will  be  necessary  where  the  minimum  fatal  dose 
of  the  standard  is  more  or  less  than  that  mentioned  in  the  table  of 
proposed  standard  values,  such  correction  to  be  made  as  per  illus- 
