11 



of 11 selected plots, in the grain for the 10 years 

 1872-81. Further selections and determinations should 

 be made after the completion of another period of 10 

 years, that is to 1891 inclusive. 



Many determinations of nitrogen, both in the wheat 

 grain, and its Mill products, and also in the straw, are 

 jjiven in No. 10 ; also in some other papers, and 

 especially in No. 65. 



The duplicate ashes are in each case mixed, if the 

 results as to actual and percentage amount are suffi- 

 ciently accordant ; and if not a check quantity of the 

 dry produce is burnt. 



From the collection of ashes so obtained, of the grain 

 and of the straw of each plot, in each year, 253 indi- 

 vidual, or " mixed year" samples have been submitted 

 to complete analysis. Thus, in the case of 3 selected 

 plots, the ashes (of both grain and straw), of each of the 

 last 16 of the first 20 years of the experiments have so 

 been analysed. In the case of 9 selected plots, the 

 ashes of the produce of 4 selected seasons, within the 

 same 20 years, have been analysed ; and in the case of 

 10 selected plots, proportionally made, " mixed-year " 

 samples of ash (of grain and of straw respectively), 

 have been analysed for the 10 years 1852-61, and 

 again for the 10 years 1862-71. 



In the case of some plots, analyses of the ash of the 

 grain, and of the straw, respectively, representing the 

 10 years 1872-81, and the 10 years 1882-91 should be 

 made, in continuation of the results already obtained for 

 the two periods of 10 years each, up to 1871 inclusive. 



The results of the 253 complete ash analyses already 

 made were published and discussed in 1884, in the 

 paper numbered 65 in the list. The results of many 

 of the nitrogen determinations were at the same time 

 given. A selection of ash analyses, and also many 

 determinations of nitrogen as above referred to, were 

 published in 1857, in the paper No. 10 in the list. 



The special object of the selection of plots for the 

 determinations of the nitrogen, and of the composition of 

 the ash, of the produce, has been to ascertain and illustrate 



