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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



absorption of the free nitrogen goes on outside these root formations, the 

 substances formed being, however, unassimilable by higher plants, but 

 through the action of nodule bacteria they are converted into an 

 assimilable form. 



Some investigators having shown that an unfruitful % soil could be 

 made fruitful if inoculated with the micro-organisms producing and 

 existing in these tubercules, various attempts have been made to carry 

 out this idea in its practical applications ; and under the name of nitragin 

 a medium was offered for the inoculation of soils with proper germs for 

 the production of the desired crop. As a scientific curiosity nitragin is 

 of great value, but in practice it has failed to yield satisfactory results. 

 The principle underlying the use of nitragin applies only to the nitrogen- 

 gathering plants. Another step has been taken in offering under the 

 name of alinit a bacterium which causes the soil to absorb atmospheric 

 nitrogen and transform it into available plant food. This preparation, 

 like nitragin, has also in practice been found to be a scientific curiosity. 



Now it must be remembered when forming any conclusions regarding 

 the "new soil science " that it is in its babyhood. We have just barely 

 recognised the fact that the bacterial life in the soil is perhaps the 

 dominant factor in agriculture and horticulture, and preparations like 

 alinit and nitragin, especially the discoveries and conclusions on which 

 they are based, are of great scientific interest, for they demonstrate the 

 fact that agricultural scientists are to-day working very close to the line 

 that divides them from discoveries of great practical value. Seven years 

 ago Sir John Lawes asked the question, " Will the day come when seeds 

 are sent out furnished with the appropriate organisms to supply the 

 deficiency in our fields ? " Before that day arrives we must know much 

 more about the micro-organisms in the soil, their life- history and 

 functions, than we do at present. We have, however, advanced far 

 enough to see that purely chemical reactions and explanations are not 

 satisfactory. The work of preparing the plant-food material in the soil 

 is done entirely or in part by living organisms. It is this germ life that 

 disintegrates, or at any rate assists in disintegrating, inorganic matter and 

 decomposes organic matter. The food cycle seems to be that the food 

 matter in the soil is first prepared by soil organisms for the plant ; next 

 it goes with the plant to the animal ; and then from the animal, after it 

 has been subjected to the action of a series of bacteria, back again to the 

 soil. If in its progress some of the nitrogen is thrown off at a tangent, 

 then it in turn is brought back again through the agency of bacterial 

 life. 



During the past century various theories have been propounded with 

 the object of explaining the cause and effect of many of the practical 

 operations and processes in soil cultivation. These theories may be classed 

 as chemical and botanical, and they constitute what is usually termed the 

 principles of agriculture and horticulture. The new soil science as yet 

 cannot be said to replace the old chemical and botanical outlook, but 

 when it does not supplant it very often supplements. 



If we set aside general conditions, such as those of- climate, locality, 

 habitat, &c., it will be found that the views of De Candolle and Liebig 

 have in the past century met with most acceptance. According to the 



