i9o6.] Use of Waste Organic Substances. ji 



considerable quantity ; the price is therefore high, and varies 

 between 7s. and 7s. 6d. per unit of ammonia. 



2. Medium grade, yielding 6 to 9 per cent, of ammonia. The 

 samples show considerable variation, and it is often difficult to 

 get any guarantee about them ; the class includes wool comb- 

 ings, wool waste, flock dust, and the poorer qualities of cloth 

 clippings. The supply is larger and prices are lower than for 

 the higher grade, but samples are not always sold on the basis 

 of their composition, and during the past year variations of from 

 5s. to 7s. per unit of ammonia have occurred. Probably 6s, 

 might be taken as an average quotation. 



These shoddies are widely used in hop gardens, and with 

 such good results that they deserve a wider trial. We have 

 seen them occasionally used with good effect on other crops ; 

 they are not so slow acting as has sometimes been stated. 



3. Low grade, yielding about 3 per cent, of ammonia. These 

 are usually offered at from 4s. to 5s. per unit, and when this 

 price includes delivery it cannot be considered high. The 

 relative manurial values of low and higher grade shoddies in 

 an ordinary rotation are being tested on the College farm. 



Refuse from Tanneries. — -Leather dust, yielding about 4 per 

 cent, of ammonia, is occasionally offered to farmers, but the 

 recorded experiments show that it has little or no manurial 

 value. Occasionally one hears of the beneficial use of leather 

 scraps in horticulture, but the results may quite probably be due 

 to other causes. 



Other tannery wastes do not appear to be much used by 

 farmers, although some of them doubtless have distinct manu- 

 rial value. 



3. Residues from Towns. 



Destructor Refuse. — From the samples of this substance sent 

 in to the College it cannot be supposed to have any greater 

 value on the land than coal ashes of equal fineness. 



Night-soil, Poudrette. — For many years it has been a standing 

 reproach to our inventive capacity that the enormous quantities 

 of night-soil obtainable in England should be almost entirely 

 wasted. On the Continent efforts have been made to convert 

 it into merchantable manures, either by dessication or by mix- 

 ing with various substances, such as peat, ashes, slaughter-house 



