i86 
Production  of  Lemon-Grass  Oil.    { Am.  jour,  pharm. 
J  ^        April,  19 1 7. 
mentioned.  It  will  be  noted  that  the  Ceylon  forms,  Nos.  6  and  13, 
are  very  low  in  oil  yield,  and  the  same  is  true  of  No.  8,  from  India. 
Both  the  yield  of  oil  and  the  citral  content  of  the  oil  have  been 
found  to  be  affected  to  a  considerable  degree  by  the  type  of  soil  on 
Table  III. 
Yield  and  Citral  Content  of  Lemon-grass  Oils  Distilled  from  the  Various 
Plants  under  Cultivation  in  1915. 
Variety. 
Yield  of 
Oil. 
Citral  Con- 
tent of  the 
Oil. 
Variety. 
Yield  of 
Oil. 
Citral  Con- 
tent of  the 
Oil. 
Per  Cent. 
Per  Cent. 
Per  Cent. 
Per  Cent. 
0.24 
80 
No. 
9  
0.20 
76 
.27 
70 
No. 
•23 
80 
.16 
73 
No. 
11  
.28 
80 
.23 
72 
No. 
12  
.29 
81 
•15 
79 
No. 
13  
.12 
85 
which  the  plants  are  grown.  Therefore,  before  selecting  a  variety 
for  commercial  planting,  tests  should  be  made  to  determine  which 
variety  will  give  the  highest  yield  of  oil  per  acre  and  the  highest 
citral  content  on  the  land  to  be  used.  The  vigor  of  the  plants  should 
also  be  considered,  since  there  seems  to  be  a  difference  in  soil  re- 
quirements among  the  varieties  tested. 
FACTORS  AFFECTING  THE  YIELD  OF  LEMON-GRASS  OIL. 
Soil  Conditions. — In  order  to  determine  the  effect  of  soil  condi- 
tions on  the  yield  of  lemon-grass  oil,  tests  were  made  in  1908  with 
the  West  Indian  variety,  No.  1,  on  soils  containing  various  degrees 
of  moisture.  On  light  sandy  soil  of  the  high  hammock  type  the 
yield  of  oil  was  0.31  per  cent,  and  on  moinst  bottom  land  0.27  per 
cent.  Another  test  on  sandy  high  pine  land  in  a  different  location 
gave  an  oil  yield  of  0.35  per  cent.,  and  on  moist  land  near  the  lake 
0.28  per  cent.  Further  tests  with  this  variety  under  other  conditions 
of  soil  moisture  gave  results  which  were  also  much  in  favor  of  the 
sandier  and  better  drained  land.  In  191 5  the  plat  devoted  to  the 
Ceylon  variety,  No.  6,  showed  a  higher  yield  of  oil  from  the  plants 
grown  on  the  high,  well-drained,  sandy  soil  than  from  the  part  of  the 
plat  which  contained  slightly  more  moisture,  0.16  per  cent,  being 
obtained  from  the  former  and  only  0.11  per  cent,  from  the  latter. 
Similar  results  were  secured  in  191 4  with  varieties  Nos.  5,  8  and  9. 
The  evidence  thus  far  available  indicates  that  for  all  the  forms 
