Remits of Experiments on Permanent Grass-land 329 



thermometer, which was provided with a porcelain tube, we were able 

 to go up to 590°. Comparisons of the platinum and gas-scales were 

 carried out at over 150 different points, each comparison consisting 

 of either ten or twenty readings of the different instruments. 



By the intermediary of the platinum thermometers a determination 

 of the boiling point of sulphur on the nitrogen scale was also made. 

 The mean of three very concordant sets of determinations with the 

 different thermometers gave 445°'27 as the boiling point on the scale 

 of the constant volume nitrogen thermometer, a value differing only 

 0°'7 from that found by Callendar and Griffiths for the same tem- 

 perature expressed on the constant pressure air scale. 



If for the reduction of the platinum temperatures in our comparisons 

 we adopt the parabolic formula, and the value of 8 obtained by assum- 

 ing our new number for the sulphur-point, we find that below 100° the 

 differences between the observed values on the nitrogen scale and those 

 deduced from the platinum thermometer are exceedingly small, and 

 that even at the highest temperatures the differences only amount 

 to a few tenths of a degree. 



Full details as to the instruments employed and the methods adopted 

 are given in the paper. 



Agricultural, Botanical, aud Chemical -Results of Experiments 

 on the Mixed Herbage of Permanent Grass-land, conducted for 

 many Years in succession on the same Land. Part III. — The 

 Chemical Results." By Sir John Bexnet Lawes, Bart., 

 D.C.L., ScJD.. F.R.S., and Sir J. Henry Gilbert, LL.D.,Sc.D., 

 F.R.S. Received August 10, 1899. 



(Abstract.) 



The experiments were commenced in 1856, and are still in progress, 

 so that the present is the forty-fourth year of their continuance. There 

 are about twenty plots, two of which have been continuously un- 

 manured, and the remainder have respectively received different 

 descriptions or quantities of manure of known composition. A report 

 on the " Agricultural Results " was published in the ' Phil. Trans.,' 

 Part I, 1880 ; and a second on the "Botanical Results " in the ' Phil. 

 Trans.,' Part IV, 1882. The present paper deals with a portion of the 

 " Chemical Results." 



In all cases, of both first and second crops, the dry matter and the 

 ash. and in most the nitrogen, have been determined. In selected cases 

 determinations have been made of the amount of nitrogen existing as 

 albuminoids, and in some of the amount of " crude woody fibre," and 

 of crude fatty matter. More than 200 complete ash-analyses have 

 also been executed. 



VOL. LXV. 2 V, 



