70 
Hyoscyamus  Niger. 
[Am.  Jour.  Pharm. 
February,  19 19. 
All  soils  contain  a  large  number  of  weed  seeds,  some  of  which 
germinate  very  quickly,  and  thus  interfere  with  germination  tests. 
The  soils  also  contain  an  abundance  of  spores  of  various  destructive 
organisms,  in  particular,  the  "  damping  off  "  fungi.  Sterilizing  the 
soil  by  heat  under  pressure  is  the  most  satisfactory  method  of 
destroying  these  destructive  agencies. 
It  had  been  previously  shown  in  germination  experiments  with 
belladonna  seeds  (5)  that  by  increasing  the  humidity  and  prevent- 
ing excessive  evaporation,  the  percentage  of  germination  was  very 
much  larger  than  where  these  factors  were  not  considered.  With 
the  above  thoughts  in  mind,  the  following  experiment  was  carried 
out.  Into  four  flats,  dimensions  12  by  20  inches,  25  per  cent,  com- 
post soil  was  placed  to  within  one  inch  of  the  top.  A  thin  layer, 
about  one  fourth  on  an  inch,  of  sand  was  sieved  over  the  soil.  The 
contents  of  the  flats  were  saturated  with  water.  Two  of  these  flats 
were  carefully  wrapped  with  heavy  manila  paper  and  then  sterilized 
in  the  autoclave  at  15  pounds  pressure  for  three  hours.  After  this 
treatment,  one  flat  was  planted  with  one  thousand  hyoscyamus  seeds 
of  sample  no.  9,  and  the  other,  with  one  thousand  seeds  of  sample 
no.  10.  Likewise,  the  two  unsterile  flats  were  planted  with  the  same 
number  of  seeds  of  nos.  9  and  10,  respectively.  All  the  flats  were 
covered  with  glass  plates  and  placed  in  the  greenhouse.  The  soil 
was  kept  moist  by  wetting  slightly  whenever  necessary. 
The  number  of  seeds  germinating  during  a  period  of  three  weeks 
was  ascertained  at  intervals  of  one  week.  The  germination  of  the 
samples  of  Hyoscyamus  seeds  in  this  experiment  are  recorded 
below. 
TABLE  II. 
Showing  the  Percentage  of  Germination  of  Seeds  of  Hyoscyamus  in 
Sterile  and  Unsterile  Soil  in  Flats. 
Sample  No. 
Treatment. 
Days  After 
Seeds  were  Planted. 
7 
21 
9 

Unsterile 
5-7 
8.1 
7-9* 
9 
Sterile 
20.1 
32.6 
33-8 
10 
Unsterile 
14.0 
16.8 
10.3* 
10 
Sterile 
30.9 
37-i 
3i-9 
*  Low  results  due  to  "  damping  off  "  fungi. 
The  results  of  the  experiment  as  presented  in  the  above  table 
show  that  in  the  sterilized  soil,  the  conditions  were  such  that  from 
