200 THE SPIRIT OF THE SOIL 



MODEL EXPERIMENT I. 



Radishes. 



The French breakfast radish is a convenient plant 

 for a preliminary experiment. Use two small boxes 

 about 3 inches deep. Fill one with your garden soil 

 or loam obtainable from a seedsman. To the other 

 box add humogen, using one-ninth of the bulk of the 

 soil (conveniently measured by a teacup) . Mix the 

 humogen and soil well. Plant the same number of 

 seeds in each box about ij inches apart and about 

 J inch deep. Water thoroughly, interchanging the 

 position of the boxes weekly, so as to insure similar 

 treatment. A window-ledge or a site in the open 

 garden is suitable, but in the former case care must 

 be taken with the watering, as in such conditions 

 the soil dries rapidly. The best plan is to plunge 

 the box up to the edge in the soil, when watering 

 will be reduced to a minimum. 



The radishes should be pulled when ready for 

 eating from both boxes at once, and the following 

 points noted : 



1. Number of plants in each box. 



2. Weight of complete plants in each box. 



3. Weight of edible portion in each box. 



4. Divide weights in each box by number of plants 

 in each box to get a comparison of the average weight 

 of the roots. 



5. Notice the quality as well as the quantity. 



6. Determine percentage increase by multiplying 

 the weight in the box treated with humogen by 100. 



