122 Tiro Sett of E.rperimentx 



atmosphere and partly from decaj'iiig turf; while tiie 

 deep-rootiug plants have deeply cultivated the land, 

 bringing up food from depths hitherto untouched, and 

 manufacturing, by the acids in their roots, inert into 

 active plant food. The humus has played its part, 

 too, by converting into active plant food tlie dormant 

 mineral constituents of the soil. 



From what has been previously shown, it is evident 

 that Professors Somerville and Middleton (who have 

 managed the Cockle Park experiments) have simply 

 remained in the experimental groove they inherited; 

 and it will be satisfactory to the reader to find 

 that they do not now seem to have one word to 

 say in its favour as a complete method of investi- 

 gation. Dr Somferville occupied the chair when I read 

 my paper at Cambridge, and Professor Middleton was 

 also present. As the reader will perceive, if he turns 

 to the lecture, I stated in a more condensed form what I 

 have treated in greater detail in this chapter, and showed 

 that in all future experiments, as regards plants and 

 animals, we require two sets of experiments — one with 

 exhausted British soil, and the other with soil brought up 

 to a good state of fertility by natui*al agencies, such as 

 those employed at Clifton-on-Bowmont. When the time 

 came for discussion neither Dr Somerville nor Professor 

 Middleton, nor any one of the audience, had any objec- 

 tion to make to the very obvious points which I have 

 just alluded to, so they may be held to have been 

 ratified by the entire audience. Toward the close of 

 my lecture one of the audience was overheard saying 

 to a neighboiu-, " Your profession is at an end, anyhow." 

 At first sight, indeed, this might seem to be so, but, as 

 I pointed out in my lecture, the services of the chemist 

 and the manure merchant will never be more thoroughly 

 appreciated than they will be when our soils are brought 

 into a high state of fertility by a proper admixture of 

 humus. 



From what I have previously shown, it is evident 



