WATER CONTENT AND ASH OF PLANTS 



165 



production and transportation of the carbohydrate com- 

 pounds, as starch and sugar, and thus indi r ectly in the 

 formation of all organic matter. In sugar- 

 and starch-producing crops, as sugar-beets 

 and potatoes, it takes an important part in 

 the growth and development. Potassium 

 doubtless has much to do in the way of 

 regulating the acidity of the sap by forming 

 organic salts such as potassium bitartrate in 

 grapes. At the time of seed formation 

 there is a slight retrograde movement 

 of the potash, in some cases a small 

 part being returned to the soil. The 

 supply of available potash in the soil has 

 great influence upon the vigor of plant 

 growth. Weak and sickly plants are always 

 deficient in potash. Some crops require 

 more for growth than do others and some 

 experience difficulty in obtaining it. Some 

 plants contain such large amounts of potash 

 that they are called " potash plants." Fig 70 _ plants 



Experiment 41. Alkalinity of ashes. Weigh 2 without potash, 

 grams hard wood ashes into a beaker containing 100 cc. H 2 O. Heat 

 over a sand-bath until it boils ; filter. To one-half of filtrate, add 

 10 drops of cochineal solution ; from the burette (see Fig. 38), add 

 dilute (i cc. acid, 40 cc. H 2 O) HC1 until the solution is neutral. 

 The alkali in wood ashes is mainly K 2 CO 3 which is neutralized 

 with HC1. Write the reaction. Test both leached and unleached 

 ashes. Note number of cubic centimeters HC1 used in each case. 

 What do the results indicate ? 



214. Sodium. This element, which resembles potas- 



