H2 THE SPIRIT OF THE SOIL 



on lines similar to those promoted both by the 

 vitamines of Funk and the accessory food bodies of 

 Hopkins. And it should also be stated that, in the 

 opinion of Professor Bottomley and his co-workers, 

 the substances with which he is dealing are more 

 closely related to the accessory food bodies of 

 Hopkins than to the vitamines of Funk. 



When Professor Bottomley first called attention 

 to the existence of these substances in peat, he 

 stated that further work was being undertaken with 

 a view of clearing up the nature of the substances 

 involved, and of defining their properties. While 

 the present volume was in course of preparation a 

 further paper was published in the Proceedings of the 

 Royal Society, and in it he describes the bodies under 

 the new term of auximones (from avgi/mos, promoting 

 growth) . 



While the experiments described above were very 

 necessary to establish conviction, they had the great 

 drawback that long periods were required for carry- 

 ing them out. The delay involved in order to test 

 whether or not a given solution contained auximones 

 was considerable, five or seven weeks being required 

 to enable the plants tested to grow sufficiently to 

 put the matter beyond dispute. It is clear that 

 there would be an immense saving of time if the 

 same result could be obtained by treating rapidly 

 growing bacteria with the substance, and further it 

 was obviously of great importance from the stand- 

 point of the main research to know what influence, 

 if any, the auximones had on the growth of the 

 nitrogen-fixing organisms. Azotobacter chroococcum 



