Sg 2 
Miller. — A Physiological Study of the 
petroleum ether was removed. The neutral oil thus obtained was placed in 
small tightly corked bottles until ready for analysis. 
Methods of Analysis. 
Upon the ether extract of the seed and of the cotyledons and hypocotyls 
at the different stages, the following constants were determined in duplicate: 
free fatty acid, saponification value, total insoluble acids, total soluble 
acids, iodine number, and acetyl value. The saponification value, total in- 
soluble acids, total soluble acids, and iodine number were determined for the/ 
neutral oil of the seed and cotyledons at the different stages of the seedling. 
The amount of ether extract in percentage of the dry material and in grammes 
per ioo cotyledons and hypocotyls was determined for each stage of the 
seedling examined. 
All of the determinations, with the exception of those noted below, 
were made according to the official methods of the American Association 
of Official Agricultural Chemists. 
The iodine number was estimated by the method of von Htibl. 
For the estimation of the acetyl value the following course was 
followed : 
A quantity of oil was heated for two hours with twice its volume of 
acetic anhydride in a round-bottomed flask with a reflux condenser. The 
acetylated oil was then transferred to a large beaker and boiling water 
added. After boiling for half an hour the water was siphoned off. This 
process was repeated a second and a third time, after which the acetylated 
oil was shaken up with petroleum ether in a separatory funnel in order to 
remove all the water from the oil. The petroleum ether solution of the 
acetylated oil was then placed on the water bath and part of the petroleum 
ether distilled off. The concentrated solution was then transferred to 
a closed vessel connected with the filter pump, and the vessel heated on the 
water bath until all the petroleum ether was driven off. A weighed portion 
of the oil thus acetylated was then saponified in the usual manner and the 
acetyl saponification value determined. The excess of sodium hydroxide 
N 
was titrated with — HC1, the alcohol driven off on the water bath and the 
2 
N . . 
acids precipitated by — sulphuric acid. The flask containing the precipitated 
2 
acid was then filled to the neck with boiling water and heated on the steam 
bath, until the insoluble acids collected in a layer at the top of the flask. 
The insoluble acids were then solidified by the immersion of the flask in ice 
water, after which the liquid content of the flask was filtered and the filtrate 
collected. Hot water was again added to the flasks, and the same process 
repeated a second and third time. The collective filtrates were then 
