496 



Utilization of Pond Mud. [nov., 



Probably this is due to the presence of calcium carbonate in 

 the Thames water, from which the Kew lake is fed, and also 

 to the shells of various molluscs which are abundant in the lake. 

 The only harm that might possibly result from the use of this 

 mud would arise if it were allowed to lie as a cake, so that air 

 was excluded from the roots. The mud at Kew is the silt from 

 the Thames water and contains decomposed vegetable matter 

 from the surrounding trees, &c. ; when first taken out it has 

 almost the consistency of clay, and in this condition is unsuit- 

 able for use. The practice at Kew is to drain off the water 

 from the lake, and when the mud can be cut out with spades 

 it is carried in barrows on to the banks where it is allowed to 

 lie and drain until it can be broken up easily. It is then 

 -distributed over the lawns, woods, beds, &c, where under 

 the influence of weather it soon breaks down. If used on 

 beds or borders it is forked over, and mixed with the other 

 soil soon after it has been put on. For lawns it is used in 

 the proportion of about twenty loads to the acre, it is then 

 t:hain harrowed and raked, and after that it soon works down 

 below the grass. When the lake was first cleaned out in 1892 

 to 1894 the mud was found to be 5 ft. deep in some parts, and 

 altogether some thousands of loads were removed. 



An analysis has been made of the mud taken from the Kew 

 lake, and also of some pond mud from Nottinghamshire. The 

 sample from Kew contained 45*15 per cent, of moisture and 

 -that from Nottinghamshire contained 78-81 per cent. ; in 

 order to enable them to be compared, the results are given in 

 the following table free of moisture : — 





Sample 

 from Kew. 



Sample 

 from Notts. 



Organic matter* and loss on heating 

 Oxide of iron and aluminium 

 Lime 



Magnesia, alkalies, &c. 

 Carbonic acid 

 Phosphoric acid 

 Insoluble siliceous matter ... 



Per cent. 



11-30 

 8-17 



12*04 

 0-97 

 8-85 

 0*27 



58-40 



Per cent. 

 27-71 



io'45 

 7-79 



} 7'05 



0*32 

 46-68 



Total 



100 



100 



* Containing nitrogen 

 Equal to ammonia 



OH39 

 o-533 



0-862 



