INFLUENCE OF MANURES ON GRASS LAND. 147 

quantity. And, similarly, it would be erroneous to conclude 
that, because there is only 16 per cent. of clover in the yield 
of Plot 3, the kainit has had a repressing influence on this 
plant. When the weight of hay is taken into account it is. 
seen that there is as great a weight of clover produced on Plot 3, 
as on Plot i, in other words, the increase in the aggregate 
yield induced by the use of kainit has taken the form of an 
increase in the abundance of plants other than clover. 
In connection with the educational work of the Department 
of Agriculture of the Durham College of Science, eight stations, 
each comprising 16 plots of 4, acre, were laid down on old 
erass land in the county of Cumberland in the winter of 1894- 
g5. In the case of four of these stations (called Set 1) certain 
manures have been annually applied to the five crops of 1895, 
to 1899. Inthe first year the standard in the case of super- 
phosphate and kainit was fixed at 34 cwt. of each per acre, 
but in the second and subsequent years only 24 cwt. of each 
of these manures was used, With the exception of this slight 
modification no change has been made in the system of 
manuring. 
In the case of the four stations constituting Set 2, the 
manurial dressings were applied in 1895, 1897, and 1898,. 
while nothing was used in 1896 and 1899. 
The value of a botanical analysis depends entirely on the 
method of sampling, and on the accuracy of the subsequent. 
separation of the species. The most exhaustive examination 
of the various systems of sampling, and their influence on the: 
results, was probably that undertaken by Dr. A. Voigt, and. 
described in vol. xxiii. of ‘‘ Die Landwirtschaftliche Jahr-. 
bicher.” The essential principles of his system have been 
observed in all the work of hay or grass sampling undertaken 
by the Durham College of Science. In the case of the Cum- 
berland plots under review the method of procedure was as 
follows : In July, 1899—when the crop of the various stations 
was ripe—Mr. W. T. Lawrence, the Superintendent of the 
Farm School at Newten Rigg, and Mr. F. Wakerley, of the 
Agricultural Department of the College, visited each place, 
the work of cutting the crop commencing after their arrival. 
Mr. Lawrence concerned himself entirely with the weighing 
2 
