520 SCIENCE PROGRESS 



Board is, as usual, of a thoroughly sound and practical nature, and now, as ever, 

 forms a model on which other work of the kind might well be based. So much of 

 the work done with the aid of State grants for the study of fishery problems is 

 devoted to subjects of remote interest to the fisheries, that one is glad to see the 

 Scottish Fishery Board devote their energies to subjects of real importance. 



J. T. Jenkins. 



AGRICULTURE 



The Spirit of the Soil ; or, An Account of Nitrogen fixation in the Soil by 

 Bacteria and of the Production of Auximones in Bacterised Peat. By 

 Gordon D. Knox, with a Foreword by Prof. W. B. Bottomley. 

 [Pp. xiii + 242 with 17 illustrations.] (London : Constable & Co., 191 5. 

 Price 2s. bd. net.) 



The Spirit of the Soil introduces us to a novel venture in scientific publication, 

 for it presents the discoveries of the man of science as seen with the eye of the 

 trained journalist. Mr. Knox has done his work well. He gives us a vivid 

 account of Prof. Bottomley's discoveries. He describes in vivacious language 

 the doings of the spirits of the soil — though why bacteria should be regarded 

 as spirits is not patent. He champions with unfaltering staunchness the virtues 

 of bacterised peat. In spite, however, of the excellence of Mr. Knox's " Boswell " 

 to Bottomley's Johnson, we hope that this method of vicarious publication will not 

 become fashionable among our men of science. 



Readers of the daily press are already familiar with Prof. Bottomley's 

 discoveries. Briefly, these discoveries may be stated as follow : Some kinds of 

 peat when treated with certain bacteria give rise to large quantities of soluble 

 humates. When the humating spirits are exorcised — by heat-sterilisation — the 

 humated peat is used as a seed-bed for nitrogen-fixing bacteria, and after the 

 latter have been at work for some time bacterised peat is produced. This 

 preparation appears to have valuable manurial properties. So potent, indeed, 

 are the effects of even small dressings of bacterised peat applied to plants 

 that Prof. Bottomley was led to inquire how they are produced. He has reached 

 the conclusion that the effects are due to the presence in the bacterised peat 

 of " accessory food bodies," or, as he calls them, auximones. This discovery 

 is of course of even greater importance than that relating to the manurial value 

 of bacterised peat, for it necessitates the conclusion that modern theories of 

 plant nutrition must be discarded or at least underpinned. The discovery 

 of auximones and the fundamental part they play in the nutrition of plants will, 

 if verified, invalidate the current view that plants may reach their full development 

 on a diet of water, carbon-dioxide, and inorganic compounds of nitrogen, potassium, 

 lime, phosphorus, and the like. 



The discovery of auximones and their sovereign role in the nutrition of plants 

 imposes on physiologists a pretty paradox. For, as is well known, the vitamines 

 required by animals are derived from plants, whence it follows that the plant 

 can supply this indispensable form of nourishment to the animal but cannot 

 make supplies for itself. 



When we survey the evidence on which these claims are based we are bound 

 to admit that it offers strong testimony to the manurial value of bacterised peat. 

 Many of the illustrations in Mr. Knox's volume show plants grown with and 

 without bacterised peat, and the superior vigour of the former is most striking. 

 We have ourselves seen not a few of the originals — grown at Kew under careful 



