1917] ' DENNY— PERMEABILITY 481 



those substances that appeared to be significant as judged by the 



experiments 



tests. 



About 10 pounds of unroasted peanuts were shelled, the pods 

 discarded, and the seeds put at once into cold water to soften the 

 seed coats; as soon as the coats were moist enough, they were 

 removed from the embryos, and dried on blotting paper in the 

 air. The water in which the seeds had been soaking was brownish 

 in color; it was made up to a volume of iooocc, with distilled 

 water; this was called the "preliminary extract/' and later its 

 content of tannins was determined. 



The air dried seed coats were divided into two lots, one lot to 

 undergo extraction in a manner comparable to the extractions 

 performed in the experimental work, and the other lot held as a 

 check to determine the original composition of the membrane before 

 extraction. The first lot was extracted with water, by putting the 

 membranes into cold water, raising the temperature of the water 

 to boiling point, and holding it at this temperature for 5 minutes; 

 the water was then drained off through a filter, and the residue 

 washed with cold distilled water until only, a faint straw-colored 

 liquid passed through the filter. The filtrate was made up to 

 1500 cc, and was called the "hot water extract." The residue 

 was vacuum dried, placed in Schleicher and Schull extraction cups, 

 and extracted in a Soxhlet extractor for 4 hours with acetone. 

 The extract was made up to a volume of 250 ccm. and was called 

 the "acetone extract." The insoluble material was called 



a 



residue." 



Methods 



timated 



thal's method (7, p. 150). The distribution of tannins in the 

 preliminary extract, in the hot water extract, and in the acetone 

 extract was determined. 



The lipoids in the acetone extract were estimated by removing 

 a sample, evaporating in a Jena glass dish, and drying to constant 

 weight in a desiccator. To obtain the amount of lipoid in the hot 

 water extract a sample was taken; strips of filter paper were dipped 

 in the samDle until the liouid was absorbed bv the filter paper: the 



