CHAPTER III. 



FURTHER EXPERIMENTS ON NUTRITION". 



SECTION A. Water-culture. 



SECTION B. Experiments on Fungi and on Drosera. 



SECTION C. Absorption and other functions of the root. 



SECTION A. Water- culture. 



(74) Method. 



To show what elements are necessary for the 

 development of a green plant, and the relative proportions 

 in which they are absorbed by its roots, the method of 

 water-culture should be used, either alone or in com- 

 bination with studies on the ash obtained by incinerating 

 the plants cultivated. 



Full directions for conducting water-culture experi- 

 ments are given in Sachs' Lectures, Eng. ed. Lect. xvu. 

 p. 283, and in Detmer's Praktikum, ch. I. pp. 1 6 1 . 



Although we have never succeeded in preventing the 

 failure of a small proportion of such experiments, the 

 liability to failure may be much diminished by careful 

 attention to the following precautions. The cylinders 



1 Compare also Acton, Proc. lloyal Soc. Vol. XLVII. (1889), pp. 

 152-157. 



