CONTRIBUTIONS FROM THE WISLEY LABORATORY. 325 



quoted, this would have added over 144 lb. of combined nitrogen to 

 that area, an extraordinary dressing, equalling the amount contained 

 in about 10 cwt. of nitrate of soda, or, if only half were in an available 

 condition, equal to the very heavy dressing of 5 cwt. of nitrate of soda 

 to the acre. The results certainly do not justify the assumption that 

 its composition was anything like this. 



This failure is distinctly disappointing, coming on to]) of those 

 of the outdoor trials last year, and, taking into consideration the 

 remarkable results obtained indoors in the first series, strengthens 

 the belief that differences in mode of manufacture or accidents during 

 the process may be answerable for the differences in the behaviour 

 of the material. Until it is possible to place upon the market a 

 material of standard composition, or at least varying within narrow 

 limits in its behaviour, it is too soon to recommend the wide applica- 

 tion of what may, under other conditions, prove to be a very valuable 

 manure. 



I have already alluded to the suggestions made by Dr. Keeble with 

 regard to Series 3 of these experiments, and I have also to acknowledge 

 the kindness of Professor Bottomley in supplying the peat, and the 

 active assistance at different times of Messrs. J. K. Ramsbottom, 

 G. M. Owen, L. C. Edwards, H. C. Powell, W. C. Croom, H. J. 

 Barker, and other senior students in carrying out the work connected 

 with the experiments. 



Summary and Conclusions. 



(1) Bacterized peat is a preparation of bog moss acted upon by 

 certain bacteria, and subsequently used as a culture medium for the 

 development of nitrogen-fixing bacteria. The exact details of its 

 manufacture are not divulged. On this account most of the experi- 

 ments possible with it are of an empirical nature. 



(2) An endeavour was made to ascertain whether it had a stimu- 

 lative effect upon growth, and three samples were received in 1914 

 and one in 1915, all from Professor Bottomley, and used in five 

 separate series of experiments. 



(3) In Series 1, carried out indoors on various plants, the results 

 were extraordinary and very uniform, growth being greatly increased 

 by the use of the bacterized peat (p. 308). 



(4) In Series 2, carried out in the open on three different kinds of 

 plants, the results, while somewhat in favour of bacterized peat, were 

 not what we had been led to hope for (p. 311). 



(5) Series 3 was designed principally to see whether the some- 

 what dry summer was to blame for the comparatively small benefit 

 seen outdoors, but on turnips the increase due to peat when ample 

 water was available was only about 9 per cent, (nothing approaching 

 that seen in the indoor experiments) (p. 315). 



(6) A comparison was also made as to the result obtained by the 

 use of a light dressing of farmyard manure (20 tons to the acre), the 



