On Manures. 223 



be more equally distributed. Where straw is scarce, they 

 are used as a substitute for litter ; and the urine greatly con- 

 tributes to the decomposition of the shells. 



Sea-sand, with a mixture of shells, is used with much suc- 

 cess as a manure, on the coasts of the North and East Riding 

 of Yorkshire (* 33 ) ; in Devonshire, and Cornwall (* 34 ), in 

 Caithness, and on the coast of Buchan in Aberdeenshire. It 

 is particularly useful in strong clays, as both its component 

 parts, (sand and shells), are beneficial mixtures in a clay soil. 



7. Coral. This substance is greatly superior to common 

 shells, as a manure. On the coasts of Devonshire and Corn- 

 wall, it is found mixed with the common shelly sand (* 35 ) ; 

 but in some of the Western Islands of Scotland, it exists in 

 considerable quantities, almost unmixed, and has frequently 

 been tried with great success. In the parish of Southend, 

 in Argyleshire, there is a bank of fine coral, about 100 yards 

 from the sea-mark. It is considered to be superior to lime 

 for moist heavy lands. To gardens it is of signal service, 

 and it likewise improves pasture and heath lands (* 3tf ). 



8. Soapers' Waste. This is considered to be a useful ma- 

 nure of a calcareous nature, with a proportion of other sub- 

 stances mixed with it. It is best calculated for grass lands, to 

 the beneficial effects on which the gypsum, and saline sub- 

 stances which it contains, must necessarily contribute. It is 

 likewise of use to peaty soils, and is excellent for gardens, from 

 its destructive effects on insects. The average quantity ap- 

 plied, is about 100 bushels per statute acre, but greater quan- 

 tities have been used with success. It is advantageously em- 

 ployed in compost. Autumn is the best season for applying 

 this manure to grass lands. For arable lands, the quantity 

 should be greater than for grass lands, and greater on strong 

 soils, and on peat, than upon light loams, and least of all, on 

 dry soils and gravels ( 237 ). It is too weighty a substance to 

 be carried to any distance. 



9. Gypsum, or Plaster of Paris. This manure was dis- 

 covered by Mr Mayer, a German clergyman of uncommon 

 merit, in 1768, and it has since been applied, with signal 

 success, in Germany, Switzerland, France and America. If 

 in England it has not been so much approved of, it must be 

 owing to the circumstance, that the calcareous principle there 

 almost universally prevails. Gypsum consists of sulphuric 

 acid and lime, and its application to crops of cultivated grasses, 

 in such moderate quantities as five or six bushels per acre, 

 is often attended with great effects. The ashes of sainfoin, 

 clover, and lucerne, when these plants are calcined, afford 



