Am.  Jour.  Pharm 
October,  1910. 
|  Cardiac  Stimulants  and  Depressants. 
463 
obtained  by  chemical  assay  as  described  in  the  article  mentioned 
above. 
Chem.  Assay  Phys.  Assay,  Min. 
No.             Preparation                Gramme  Digitoxin        Lethal  Dose  for  a  Lethal  Dose  of 
in  100  c.c.                250  Gm.  Pigs  z  c.c.  of  Tinct. 
1  Tinct.  U.S.P  0.0326                  0.8    c.c.  0.02608 
2  Tinct.  U.S.P  0.0329                  0.8    c.c.  0.02630 
k  3    Tinct.  U.S.P  0.0290                   1.0    c.c.  0.02900 
4  Tinct.  U.S.P  0.0280                   1.1    c.c.  0.03080 
5  Tinct.  U.S.P  0.0380                  0.9    c.c.  0.03420 
6  Tinct.  Fat  free                     0.0410                  0.9    c.c.  0.03690 
7  Tinct.  Fat  free   0.0328                   1.1    c.c.  0.03690 
8  Tinct.  Fat  free                    0.0375                  0.9    c.c.  0.03375 
9  Tinct.  Fat  free   0.0440                  0.75  c.c.   '  0.03300 
10  Tinct.  Fat  free   0.0240                  1.25  c.c.  0.03000 
11  Tinct.  Fat  free                    0.0365                  0.8    c.c.  0.02920 
12  Tinct.  Fat  free                     0.0290                   1.0    c.c.  0.02900 
13  Powdered  Ext  0.763  per  cent.       0.031  Gm.  0.02370 
Average  0.03061 
A  study  of  the  table  of  March,  1908,  shows  that  an  assay  of 
about  0.025  Gm.  digitoxin  per  100  c.c.  corresponded  closely  with 
a  lethal  dosage  for  240  Gm.  guinea  pigs  of  about  1  c.c.  A  careful 
scrutiny  of  the  above  results  shows  not  quite  so  uniform  an  agree- 
ment, but,  on  the  whole,  a  minimum  lethal  dose  of  1  c.c.  cor- 
responds fairly  closely  with  an  assay  of  0.030  Gm.  digitoxin  per 
100  c.c.  The  third  column,  consisting  of  figures  representing 
the  products  obtained  by  multiplying  together  the  figures  in  columns 
1  and  2,  shows  how  nearly  concordant  the  results  obtained  ran, 
and  corresponds  to  percentage  of  digitoxin  calculated  from  a  lethal 
dosage  of  1  c.c.  of  tincture,  0.1  c.c.  of  fluidextract,  or  0.025  Gm. 
powdered  extract.  The  average  of  this  column  is  0.0306.  Con- 
tinued work  on  this  interesting  assay  has  shown  that  the  purity 
of  the  crystalline  digitoxin  obtained  depends  largely  on  the  manipu- 
lation of  the  bulky  lead  subacetate  and  sodium  phosphate  precipi- 
tates (see  Amer.  Jour.  Ph.,  1908,  p.  118).  A  centrifuge  is  now 
being  installed  in  our  laboratory  suitable  for  sedimenting  these 
preparations, — and  by  its  use,  it  is  hoped  that  a  higher  degree  of 
purity  of  the  separated  digitoxin  will  be  obtained,  insuring  results 
still  more  nearly  concordant  with  physiologic  assay. 
Aconite  Root  and  Leaf. — The  chemical  assay  methods  employed 
for  all  aconite  preparations  in  the  following  table  were  essentially 
those  of  the  U.S.P. 
