ON THE MIXED HERBAGE OF PERMANENT MEADOW. 
1405 
some of the weeds was notably increased, and of these, that of JRumex Acetosa was the 
most prominently so. 
Referring to what has been stated to he one of the main objects of the experiment— 
to determine whether the mineral constituents, and the nitrogen, contained in one ton of 
hay would yield one ton of increase, it has been stated generally that only about three- 
quarters of a ton instead of one ton of increase has been obtained. This is almost 
precisely the amount reached over the average of the 16 years of the experiment. Over 
the first 10 years, however, the increase amounted to an average of only half a ton ; 
but during the succeeding six years, in five of which second crops were removed, it was 
much higher, giving the average of three-quarters of a ton increase for the whole 
period, as above stated. It is obvious that, with an excess of manure on the manured 
plot, the exhaustion by the removal of the second crops will be much less on it than on 
the unmanured plot; and hence the amount of the produce calculated as increase over 
that without manure will be the greater. There was also a considerably increased 
yield of both mineral matter and nitrogen over the later as compared with, the 
earlier years, due to the removal of second crops. Still, there was, over the whole 
period, scarcely more than half of the supplied nitrogen estimated to be recovered; 
and even over the last six years, in five of which second crops were removed, there 
was, so far as can be estimated, only about two-thirds of the annually supplied nitrogen 
annually recovered. In fact, when, as is now done, the results of five more years, in 
four of which second crops were removed, are brought into the calculation, the general 
conclusions as stated in Part I., where the points under discussion, and the explana¬ 
tion of the facts, are more fully considered than would be appropriate here, are not 
invalidated. 
Finally, as will be judged from the results of the separations which have been 
considered, the general aspect of this plot was not widely different from that of the 
unmanured plots ; but it exhibited a greater preponderance of grasses, and some 
increased depth of colour, and luxuriance. The appearance of the herbage was, 
nevertheless, upon the whole, that of restricted growth. 
17. Farmyard manure, alone, and with ammonia-salts in addition; Plots 2 and 1. 
We now turn from the consideration of the effects, on the botany of the plots, of 
more or less complex artificial mixtures of the various constituents of manure, to those 
of the very complex and heterogeneous natural manure, farmyard dung. To plot 2, 
farmyard manure, at the rate of 14 tons per acre per annum, was applied for eight 
consecutive years, from 1856 to 1863 inclusive. To plot 1, the same amount of 
farmyard manure was annually applied over the same eight years, but with 200 lbs. of 
ammonia-salts (supplying about 43 lbs. of nitrogen) per acre per annum, in addition. 
After the eight years, the application of dung was discontinued on both plots ; 
plot 2 remained from that time entirely unmanured; plot 1, however, still received 
the same annual application of ammonia-salts as previously. 
MDCCC LXXXII, 8 R 
