OF AGRICULTURE. 41 



mentally grown wheat- grain have been sent to the 

 mill, and the proportion and composition of the 

 different mill-products has been determined. 



In the sugar-beet, mangel-wurzel, and potatoes, 

 the sugar in the juice has in many cases been de- 

 termined by polariscope, and frequently by copper 

 also. 



In the case of the experiments on the mixed 

 herbage of permanent grass-land, besides the samples 

 taken for the determination of the chemical com- 

 position (dry matter, ash, nitrogen, woody fibre, 

 fatty matter, and composition of ash), carefully 

 averaged samples have frequently been taken for 

 the determination of the botanical composition. In 

 this way, on four occasions, at intervals of five years 

 — viz., in 1862, 1867, ^72, and 1877 — a sample of 

 the produce of each plot was taken, and submitted 

 to careful botanical separation ; and the percentage, 

 by weight, of each species in the mixed herbage 

 determined. Partial separations, in the case of 

 samples from selected plots (frequently of both first 

 and second crops), have also been made in other years. 



Samples of the soils of most of the experimental 

 plots have been taken from time to time, generally 

 to the depth of 9, 18, and 27 inches; sometimes to 

 twice, and sometimes even to four times this depth. 

 In this way more than 1000 samples have been 

 taken, submitted to partial mechanical separation, 

 and portions of the fine soil (that is, excluding 

 stones) have been carefully prepared and preserved 

 for analysis. In a large proportion of the samples 

 the loss on drying at different temperatures, and at 

 ignition, has been determined. In most, the nitrogen 

 determinable by burning with soda-lime has been 

 estimated. In many the carbon, and in some the 



