viii PREFACE 



win a livelihood, for it is only when the abundant 

 nitrogen in the air and in decaying organisms has 

 been combined into suitable chemical compounds 

 that it becomes available as a plant food. The work 

 of Professor Bottomley has been concerned ex- 

 clusively with the activities of these organisms, and 

 his object has been to find a means for giving them 

 an environment in which they can freely develop. 

 His aim has been in fact to do for the bacteria the 

 same service that the gardener and farmer perform 

 for the plants that they cultivate. Husbandry is 

 the oldest of the arts and sciences, bacteriology the 

 youngest. In this book I have attempted to indicate 

 some of the results that will certainly follow from 

 soil inoculation. I am not suggesting that Pro- 

 fessor Bottomley has found the whole truth, that 

 later workers will not achieve the results that he can 

 claim by more suitable methods. I think, however, 

 that the evidence collected in the following pages 

 will convince the reader that a notable advance has 

 been made in horticulture, and that a new discovery 

 of momentous consequence has been made in the 

 accessory food bodies or auximones, a discovery 

 that will complete and round off the corresponding 

 discovery of vitamines and their relation to the 

 health and growth of animals. Lastly, I have pre- 

 pared the book in the hope that farmers and gar- 

 deners will, as they alone are able to do, carry these 

 experiments into the wider field of everyday life. 

 Farming and gardening are arts requiring expert 

 knowledge. It is only reasonable to suppose that 

 laws and conditions, comparable with those governing- 



