22 POXINDATIONS OF BOTANY 



EXPERIMENT IX 



Extraction of Oil by Ether or Benzine. — To a few ounces of 

 ground flaxseed add an equal volume of ether or benzine. Let it 

 stand ten or fifteen minutes and then filter. Let the liquid stand in 

 a saucer or evaporating dish in a good draught till it has lost the 

 odor of the ether or benzine. 



Describe the oil which you have obtained. 



Of what use would it have been to the plant ? 



I£ the student wishes to do this experiment at home for himself, 

 he should bear in mind the following : 



Caution. — Never handle benzine or ether near a flame or stove. 



A much simpler experiment to find oil in seeds may readily be 

 performed by the pupil at home. Put the material to be studied, e.g., 

 flaxseed meal, corn meal, wheat flour, cotton-seed meal, buckwheat 

 flour, oatmeal, and so on, upon little labeled pieces of white paper, 

 one kind of flour or meal on each bit of paper. Place all the papers, 

 with their contents, on a perfectly clean plate, free from cracks, or 

 on a clean sheet of iron, and put this in an oven hot enough nearly 

 (but not quite) to scorch the paper. 'After half an hour remove the 

 plate from the oven, shake ofi the flour or meal from each paper, and 

 note the results, a more or less distinct grease spot showing the 

 presence of oil, or the absence of any stain that there was little or 



no oil in the seed examined. 



« 



28. Albuminous Substances. — Albuminous substances 

 or proteids occur in all seeds, though often only in small 

 quantities. They have nearly the same chemical compo- 

 sition as white of egg and the curd of milk among animal 

 substances, and are essential to the plant, since the living 

 and growing parts of all plants contain large quantities of 

 proteid material. 



Sometimes the albuminous constituents of the seed occur 

 in more or less regular grains (Fig. 8, at Kt) . 



But much of the proteid material of seeds is not in any 



