AERATION OF THE SOIL BY EARTH- 

 WORMS 



By J. NEWTON FRIEND, Ph.D., D.Sc. 



During the past few years so much attention has been given to the 

 numerous problems connected with the corrosion of iron and 

 steel that chemists are now beginning to realise that a large 

 number of hitherto unsuspected factors are involved in the 

 change. Richard Gaines {Chemical News, 1910, 101, 205) has 

 brought forward a body of evidence to show that bacteria not 

 infrequently play an important part in the oxidation of steel 

 structures embedded in the soil and it seemed to me that the 

 common earthworm might likewise prove to be a potent factor 

 in similar cases. It is now well recognised that water, acids and 

 oxygen are essential to corrosion and it may be expected that if 

 the amounts of these three substances in the soil be increased 

 corrosion will be stimulated. It would appear that worms are 

 capable of assisting the distribution of moisture in the soil both 

 by continually burrowing in it and by swallowing and then 

 excreting it. In so far as this is the case, therefore, they may 

 assist corrosion, even although they may not add to the total 

 amount of water in the soil. 



But the chief activity of worms lies in their power of excreting 

 acids in their castings, of exhaling carbon dioxide and of aerating 

 the soil both by mechanical and by chemical means ; it was 

 with the object of determining the potency of these factors that 

 the observations now recorded were made. 



A search through the available current zoological literature 

 shows how lamentably ignorant we are of the habits and distri- 

 bution of worms. This is further emphasised by the fact that 

 although reasonably cheap text-books may be purchased on 

 practically all the usual natural history topics, we have no 

 corresponding text-book on worms. It is hoped that the infor- 

 mation contained in this paper may serve to arouse interest 

 afresh in the earthworm ; as we shall see, it has a wonderful 

 work to perform. 



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