PART II. 



EXPERIMENTS WITH SALINE SUBSTANCES, APPLIED ALONE AND 

 WITH LIME, CLAY, AND OTHER MINERAL SUBSTANCES. 



CHAPTER V. 



Wide range of agricultural experiment. Arrangement and subjects of the sug- 

 gestions contained in the present work. Experiments with saline substances 

 applied alone. General objects or aims of field experiments. Practical and 

 theoretical purposes for which experiments with single substances are made. 

 What is a successful experiment ] Can mineral or saline substances applied 

 alone be depended upon as manures for our cultivated crops on the gene- 

 rality of soils ? Circumstances in which saline or mineral applications are 

 likely to produce the most sensible effects. General suggestions for experi- 

 ments on this subject. Equivalent quantities of the different saline sub- 

 stances used in comparative field experiments. Circumstances which ought 

 to be stated in regard to all soils and localities selected for experiment on 

 publishing the results of trials made upon them. 



THE range of experiments in practical agriculture is ex- 

 ceedingly wide, and the questions to be solved by them are varied 

 and complicated almost without end. For the sake of clear- 

 ness, I shall arrange the suggestions I intend to offer under the 

 following general heads : 



I. Experiments with saline substances applied alone, and 

 with lime, clay, and other mineral substances. 



II. Experiments with natural and artificial admixtures of 

 saline substances. 



III. Experiments with natural manures, vegetable and ani- 

 mal. 



