Jan. 1897.] BOTANICAL SOCIETY OF EDINBURGH 21 



these minute organisms may be absent, and that, in con- 

 sequence, the vigorous development of the plants may 

 be prevented. Professor Nobbe, of Tharandt, and i)r. 

 Hiltner, devoted much attention to the subject, and 

 proved, amongst other things, that each Papilionaceous 

 plant has its own varietal, if not specific, organism, and 

 that for full development it is necessary that the roots of 

 a Papilionaceous crop should have access to the bacterium 

 which is specially adapted to it. They therefore instituted 

 a series of pure cultures of the various varieties of bacteria 

 that inhabit the roots of our more important Papilionaceous 

 plants, and having patented these cultures, they entrusted 

 their manufacture to the well-known chemical firm above 

 mentioned. This pure gelatinous culture is known as 

 " Xitragin," and is sold at M. 2 "7 5 per bottle, this quantity 

 being sufficient to dress a morgen. It will thus be seen 

 that for 4s. 6d. one can obtain as much Mtragin as will 

 treat an acre, so that if it produces practically any good 

 effects at all, its use can hardly fail to be profitable. 



To apply the Nitragin to the land or the crop one is 

 recommended either to mix it with water and then to add 

 the seed to the solution immediately before sowing, or to 

 mix it with some soil and afterwards scatter the mixture 

 over the field. 



Early in May I obtained a few bottles of Nitragin, and 

 at once started some small experiments to test its practical 

 value. Without going into the details of the arrangement 



CO o 



and conduct of these experiments, I may say that I was 

 careful (a) to apply the same quantity of seed to compar- 

 ative plots, (h) to see that the Nitragin was not exposed to 

 light, and was liquified at a temperature of less than 

 100° r., and (c) that in the various cultural operations of 

 covering the seed, weeding the plots, etc., the worker should 

 never go from inoculated to uninoculated ground. As a 

 matter of fact the weeding was all done from planks, each 

 plot being provided with a sufficient number, which were 

 utilized as occasion required. 



Experiments with Peas. 



Each plot consisted of a row 24 feet long, an interval 

 of 2^ feet occurring between adjoining rows. Eive 



