638 FARM ' SEEDS ' : GENERAL 



taining absolute alcohol, and gently warm over a Bunsen flame. 

 The alcohol dissolves the oil, and on pouring it into another 

 vessel of distilled water the oil separates in the form of fine 

 drops, giving a milky appearance to the liquids. When no oil 

 is present the water and alcohol remain quite clear. 



(d) Smell. — Some seeds when fresh have a characteristic 

 smell which is lost when they are old. The Umbelliferae 

 generally have oil-canals in the wall of the fruits, and the 

 odour is tolerably well-marked in fresh samples, becoming 

 fainter or disappearing altogether on being kept. Carrots and 

 parsnips are examples of this family. New oats have an earthy 

 smell which is absent in older grain. Not only is smell a 

 guide to the freshness of seeds, but musty samples injured by 

 dampness and the growth of mould are easily detected by their 

 odour. 



From the foregoing account, it- is apparent that no rehance 

 can be placed on one character only in assessing the quality 

 of seed, so far as its capacity for producing a healthy and 

 vigorous crop is concerned. Especially is this true of external 

 peculiarities, which, in many instances, can be so readily altered, 

 that judgment based upon these alone is very unsafe. The use- 

 fulness of a sample of seed depends on the number of robust 

 plants which can be obtained from it; this is governed by its 

 purity, germination capacity, and weight of its component seeds, 

 and it is upon an investigation of these characters that confidence 

 should be placed by all who are anxious to reduce failure and its 

 consequent expense to a minimum. 



