98 
Report of Experiments on the Growth of Wheat. 
who have attempted to determine on what depends the pro- 
ductive condition of a soil, by means of the chemical analysis 
of soils of different physical characters, and of known dif- 
ferent productive qualities. The opinions of Professor Magnus, 
put forth some years later, in his report upon forty-two 
analyses of soils made under the auspices of the Landes-Oeko- 
nomie Kollegium of Prussia, to which he was then chemist, 
abundantly confirm the propriety of the decision at which we 
arrived, after a very careful consideration of the subject at the 
commencement of our experiments. 
Our conclusion, as indicated in former papers, and frequently 
expressed in answer to the objections of chemical friends who had 
not paid special attention to the applications of chemistry to agri- 
culture, was, that far more had yet to be done in determining the 
chemical and physical qualities of soils in relation to the atmo- 
sphere, and to manurial substances exposed to their action, as well 
as in perfecting methods of analysis, before comparative analyses 
could aid us much in deciding upon the relative productiveness of 
different soils, to say nothing of the still more difficult problem of 
estimating, by such means, the condition of fertility or exhaustion 
of one and the same soil at different times. Of late years very 
much has been done in these departments of investigation ; still, 
as recent discussions abundantly show, far too little is even yet 
known of what a soil either is or ought to be, in a chemical point 
of view, to render the results of the analysis, of soils directly 
applicable to the solution of questions such as those we had in 
view in our enquiry. But if our knowledge of the chemistry of 
soils should progress as rapidly as it has during the last twenty 
years, the analysis of a soil will ere long become much more 
significant than it is at present. 
In the mean time, therefore, the synthetic rather than the ana- 
lytic method was relied upon. And it was with the striking 
effects of the mineral manures upon the still growing turnip-crop 
under our view, and wishing to test more fully the recently-pro- 
mulgated doctrines of Liebig, that the plan of the first of the 
twenty years of experiments with wheat was arranged. Under the 
influence of such experience, and of such theoretical considera- 
tions, " inorganic " or " mineral " manures of some kind were 
applied to almost every plot, and nitrogenous ones to very few. 
Without anticipating in these preliminary remarks the results 
which will be given in detail further on, it may be stated gene- 
rally, that in this first season scarcely any increase whatever was 
obtained from the exclusive application of any of the so-called 
mineral manures ; whilst, wherever nitrogenous manures were 
employed the effect was very striking. 
Naturally enough much more nitrogen (as ammonia or in some 
