10 
BULLETIX 442, T7, S. DEPARTMENT OF AGRICULTURE. 
results. This would indicate that high citral content can be secured 
only from plants grown on very well drained soil. 
Time of harvest. — Although the citral content of the oil does not 
appear to be greatly affected by the time of harvest, the results indi- 
cate that of the two harvests each year the oil distilled from plants 
of the first harvest contains the greater quantity of citral. Data 
covering a number of years are given in Table V. 
Table V. — Citral content of lemon-grass oil distilled from plants harvested at tiro different 
times of the year. 
Year and plants har- 
vested. 
Citral content of oil. 
Year and plants har- 
vested. 
Citral content of oil. 
First 
harvest. 
Second 
harvest. 
First 
harvest. 
Second 
harvest. 
1908. 
First plat 
Per cent. 
' 72 
74 
75 
76 
Per cent. 
74 
72 
72 
78 
1914— Continued. 
No.8 
Per cent. 
81 
75 
70 
73 
78 
80 
80 
81 
85 
Per cent. 
72 
No. 9 
59 
Third plat 
1915. 
No. 5 
1912. 
68 
No. 1 
No. 6 
71 
No.8 
78 76 
No.8 
64 
1 
78 
78 
1 
No. 9 
70 
1914. 
No. 10 
74 
No. 11 
82 
>sO. 1 
No. 12 
76 
79 
No. 5 
No. 13 
82 
No. 6 
SOLUBILITY OF LEMON-GRASS OIL IN ALCOHOL. 
For many years it was considered that good lemon-grass oil should 
be soluble in clear solution in three volumes of 70 per cent alcohol, 
and this was the test applied before the method of citral determina- 
tion was in general use. It served a useful purpose, however, inas- 
much as certain adulterations which had become quite general could 
thus be detected, but at the present time, when the valuation of the 
oil is entirely on the basis of the citral content, it is difficult to under- 
stand the reason for the continued use of the solubility test. It 
has been shown repeatedly that in many parts of the world pure 
lemon-grass oil does not pass the solubility test, especially after it 
has been stored for several months. This has been true of most of 
the samples of the oils produced in the Western Hemisphere, so that 
West Indian lemon-grass oil has come to be a synonym for insoluble 
oil. This (hs crimination has kept out of the market many West 
Indian oils of very high citral content. 
There has been much discussion regarding the factors which affect 
the solubility of the oil, it having been contended that the length of 
time of distillation is the controlling factor. In order to secure data 
upon this point the following tests were made: In 1914, 158 pomids 
of the freshly cut plants were distilled with steam and the oil drawn 
