306 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Bacillus radicicola — and after a few days' incubation at 20 degrees C. 

 is ready for use." * 



Professor Bottomley's theory appears to be that the humifying 

 bacteria produce soluble humates upon which the nitrogen-fixers 

 thrive, but we are left in the dark as to many things connected with the 

 preparation of the material, and, as a consequence, experiments with it 

 are bound to be very largely empirical in their nature. Analyses have 

 been published by Professor Bottomley f showing an increase in the 

 nitrogen content from about 1*267 per cent, in the raw peat to about 

 4*31 per cent, in the finished product, and it is difficult to believe that 

 so great an amount of nitrogen as is represented by a difference of over 

 3 per cent, should be taken from the air and fixed in the course of " a 

 few days." The probable explanation of these figures is that the 

 materia] had been under cultivation for much more than" a few days " 

 before the analysis was made. There is no theoretical reason why 

 the fixation of nitrogen should not go on for a long time in such material 

 if the moisture content and the temperature are suitable. 



Another point of importance arises from the fact that we have no 

 knowledge whatever of the price at which the bacterized peat can be 

 sold, and this prevents any proper comparison with other manures on 

 the market. 



B. — Claims made for the Peat. 



The chief claim made for the bacterized peat is that it greatly 

 stimulates growth. Minor claims are that root growth is particularly 

 encouraged, and that the root-knot eelworm, which is so troublesome 

 an enemy of pot plants, does not attack plants treated with this peat. 

 We have no evidence upon the last point, and have had no opportunity 

 of testing it ; the conclusions we have come to with regard to the other 

 two are set out below. 



C. — Material used in Tests. 



At our request Professor Bottomley was good enough to send 

 us a supply of his treated peat, which reached us at the beginning 

 of January 1914. He did not at that time send us any of the raw 

 peat, and for comparative purposes we purchased some peat-moss 

 litter, which we used in all the pot experiment controls and in some 

 of the experiments in the open. Later a supply of the raw peat was 

 also received from Professor Bottomley and was used in some cases. 

 Except that it appeared to be a little more solid than the sample 

 we had been using, it was apparently precisely like it. 



The bacterized peat was unfortunately not the same in all the 

 experiments. Four consignments were sent by Professor Bottomley 

 in all, and there was a marked difference in appearance between the 



* Bottomley, W. B., " The Bacterial Treatment of Peat," Jour. Roy. 

 Soc. Arts, vol. lxii. (1914), p. 374. 

 f L.c. ante. 



