3t'. 



THE TLAJ^'T, 



If a fariijcr -wishes to make a cart lie prcparca iiia 

 wood and iron, gets tliein all in the proper condition, 

 and then can very readily pnt them together. But 

 if he has all of the wood necessary and no iron, he 

 cannot make his cart, because bolts, nails and screws 

 are required,- and their place cannot be supplied by 

 boards. This serves to illustrate the fact that in 

 raising plants we must give them everything that 

 they recpiire, or they will not grow at all. 



In the case of our young plant the following opera- 

 tions are going on at about the same time. 



The leaves are absorbing carbonic acid from the 

 atmosphere, and the roots are drinking in water from 

 the soil. 



The manner in which food is taken up by roots, 

 may be illustrated by the following experiment : 

 Take a tumbler, filled entirely full with water ; tie 

 over it a bladder, and on the bladder sprinkle a little 

 salt. The bladder becomes moist throughout its 

 entire thickness, and transmits enough moisture to 

 the salt to dissolve it gradually, and as fast as it is 

 dissolved, it passes through the bladder into the 

 water inside of the tumbler. In a long enousrh time 

 the water can be made, in this wa^fc, to dissolve as 

 much salt as though it had been stirred into it witli- 

 "out the intervention of the bladder. If we keep the 

 salt soaking wet, as it lies on the outside of the blad- 

 der, it will pass through much more rapidly, but if 

 we do not wet it by a direct application of water, 

 enough water will reach it through the meml)rane to 

 allow it to pass into the tumbler, as alwve described. 



