too much such food material and the potato would actually lose 

 some of the water which it held. 



The experiments which have been made not only demonstrate 

 how the roots absorb water containing plant- food, but they 

 emphasize the fact that the outside solution must be very dilute 

 in order to be absorbed at all. The root-hairs, then, absorb water 

 which has dissolved only a small amount of plant-food from the 

 richness of the soil, and not such rich solutions as the sap of the 

 plant itself. 



9. The plant tnay be united, and even killed, by attempting to 

 feed it fertilizer solutions which are too strong. — More carefully to 

 test this matter relating to the use of strong 

 solutions, we may make a very simple ex- 

 periment. Secure a 3'oung radish plan"^ 

 (or almost an}^ seedling with several leaves) 

 and insert the roots into a small bottle con- 

 taining some of the saltpetre solution I. In 

 another bottle we put a similar plant with 



. some of the weak solution II. Support the 

 plant in the mouth of the bottle with cotton 

 batting. After standing for a few hours or 

 less it will be noticed that the leaves of the 

 plant in the strong fertilizer solution begin 

 to wilt, as in Fig, 4. The plant in the 

 weak fertilizer solution, Fig. 5, is perfectly 

 rigid and normal. This further indicates 

 that the growing plant is so constituted as 

 to be able to make use of very dilute solutions onh'. If we at- 

 tempted to feed it strong fertilizer solutions, these strong solu- 

 tions instead of being absorbed b}^ the plant take water from 

 the latter, causing the plant to wilt. In fact, saltpetre seems 

 to be most available for plant-food when one ounce is dissolved 

 in about seven or eight gallons of water. 



10. The injurious ejfect of stroyig fer'tilizer solntions is knozvyi i7i 

 practice. — In every-day practice we are already familiar with the 

 fact above demonstrated. Everj^one recognizes the value of 

 wood ashes as a fertilizer ; but no one would dare water his val- 

 uable plants with lye, or sow his choice vegetable seeds on an 



4. 



Killed by too much 

 food. 



