A VISIT TO KOTIIAMSTKD. 245 



ohserved that nitrates find their way more ra])idly tlirouj^h tlie 

 soil, and come sooner in contact with the rootlets of dec]) rootinjf 

 plants such as grasses, and also that tliey cli'ect a marked change 

 in the character of the lower soil and sul)Soil, rendering it more 

 porous and judN-crulcnl. I'.ut \\ lid I ht ammonia salts or nitrate 

 of soda is usetl it seems (juitc cvidrut tliat tlieir eflect is not very 

 lasting, and they cannot be relied upon to have nuich iidluence 

 on any crop save the one to which they are immediately applied. 

 A very important and still more interesting part of the in- 

 vestigation remains to be considered. The differences in the 

 bulk of crop obtained by the various modes of treatment, though 

 very marked, were as nothing compared with the extraordinary 

 diversity in tlie character of tlie cro])s upon the several plots. 

 So striking were these that it seemed almost incredilde that they 

 were due to the sole eflect of various manuring, and tliat no seed 

 of any kind had l)een deliberately sown on the original pasture. 

 Indeed the appearances of some of the plots were such as to 

 make it seem a matter of surprise that they were grass experi- 

 ments at all, and not unnaturally evoked the remark from a 

 lad}', who recently visited the station, tliat she could not have 

 believed it possible that science should have been capable of 

 spoiling so much good grass. On one plot might be seen a rank 

 luxuriant growth of cock's foot grass in full seed, on another, 

 soft silky fescues predominated, on another, meadow grasses, 

 &c. On some plots there was a rich crop of clover and vetches, 

 and on others not a vestige of a leguminous plant was to be 

 seen. One plot seemed devoted to the cultivation of the sorrel 

 dock, and others to umbelliferous plants of various kinds. This 

 divergence of character from the natural growth of the original 

 meadow-land has been growing more and more manifest every 

 year, and was early noted by the experimenters who took so 

 much interest in the matter as to cause a careful botanical 

 separation to be made of the various species found on oacli plot. 

 This has been done periodically with great care and troul)le for 

 many years, and the results are exhibited upon an elaborate 

 chart, showing "the domination of one order of plants over those 

 of others in the mixed herbage of grass land under the inlluence 

 of different manures, each applied year after year." A large 

 show case is also exhibited in the laboratory, showing the actual 

 dried herbage derived from a fair sample of each plot, and these 

 have been assorted, after careful separation, into their various 

 botanical genera and species, and so arranged as to show the 

 precise character of each plot at a glance. A few figures taken 

 roughly from a chart in the laboratory will serve to illustrate 

 the differences between a few of the plots. The figures represent 

 the averages of determinations taken at four diflerent times — 

 1862, 1867, 1872, and 1877. 



