SCIENCE WITH PRACTICE, 1812 TO 1845 99 



and Tusser hardly mention the subject. Plat is the first 

 writer who treats of it at any length. Salt sand, salt 

 water, salt weeds, and everything of a saline quality had 

 been strongly recommended by Gervase Markham in his 

 ' Farewel to Husbandry,' written in the reign of James I. ; 

 Gabriel Plattes considered that ^ sal-anioniake ' formed a 

 good mould in which to set corn ; the use of salt had been 

 urged upon farmers by Lord Bacon. But, as a rule, a little 

 half-rotted straw was the only substance used. On the 

 sea-coasts farmers might employ seaweed and sand, but 

 the prohibitive prices of laud carriage prevented their use 

 in the interior. Lime, chalk, marl, crag, gypsum, rags, 

 coal ashes, and the sweepings of London streets ^ were used 

 by farmers who found their natural manures upon the spot ; 

 but their use was necessarily local. ' Nothing like muck ' 

 was the proverbial saying, because nothing but muck 

 was obtainable. The one exception up to this time was 

 bone, which had created a new industry. Now, however, 

 as railways cheapened costs of conveyance, and drainage 

 enabled the soil to benefit by fertilising substances, science 

 provided portable means of enriching lands. Sprengel led 

 the way by investigating the properties of soil, and Liebig 

 brought chemistry to bear on the composition of new 

 stimulants in the shape of manure. From 1835 onwards 

 the use of nitrate of soda and guano gradually spread. The 

 manufacture of British guano supplied a cheaper and 

 hardly less valuable substance than its Peruvian rival. In 



' The manures enumerated by Hartlib {Legacy, 1652) are — '(1) Chalke ; 

 (2) Lime ; (3) Ordinary dung ; (4) Marie ; (5) Snaggrett [shelly earth 

 from river beds]; (6) Ouse from marsh ditches; (7) Sea Weeds; (8) 

 Sea Sand ; (9) Folding of Sheepe ; (10) Ashes ; (11) Soote ; (12) Pigeon's 

 and hen's dung ; (13) Malt dust ; (14) Salt and lime ; (15) Grassy turf 

 and brakes; (16) Fish ; (17) Urine; (18) Woollen rags ; (19) Denshyving, 

 or paring and burning ; (20) Mixing of lands ; (21) Lupines, and plough- 

 ing green plants into the ground.' 



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