ON PHOSPHATE NODULES. 115 



be realised. A few years have since elapsed, and now every tenant who 

 owns a scrap of " upper green-sand" in the neighbourhood of Cambridge 

 riddles his acres with pits. "Walk from Cambridge along any of it; 

 roads into the country, and within distances varying from the suburb 

 to two or three miles, the eye will not fail to see one, two, three, or n.oi( 

 pits in the adjoining fields. The process of acquiring the nodules there 

 is considerably more laborious than in Suffolk. Pits are dug, and tht 

 "marl" or clay is thrown into circular trenches, in which a rake or har- 

 row is drawn round and round by a horse, while water is continually 

 being pumped into it. By this means the clay is washed away, and fossil 

 shells and nodules are left behind. At Felixstow, all that is requisite is 

 to sift the sand from the nodules, which are then thrown together into a 

 heap, to be conveyed at once to the manufactory. 



When residing lately at Steyning, in Sussex, the writer himself found 

 a pit from which sand had been excavated in the lower green-sand 

 deposit, containing a mortar-like band,* with a few characteristic fossils, 

 and an abundance of balls of indurated clay, about one and a half feet 

 beneath the surface. Suspecting them to contain phosphate of lime, as 

 they much resembled specimens from Farnham, in his collection, he 

 transmitted them to Messrs. Barton Brothers, chemists, of Brighton, who 

 kindly undertook to analyze them. The result proved that they con- 

 tained over eighty per cent, of phosphate of lime — higher, in fact, than 

 any the writer has yet heard of. 



Such is a brief account of the discovery of " phosphate nodules," 

 which in less than twenty years has formed a new epoch in the history 

 of agricultural manures. Practical men have reaped golden fortunes 

 from the discovery, though few of the thousands who have benefited by 

 it, know where the phosphate nodules originally came from, or that it 

 was Professor Henslow — ever ready to impart his scientific knowledge 

 and discoveries — who first pointed them out. He rests from his labours, 

 but the results of his active disinterested mind will be of lasting benefit 

 to his country. 



* This "band" is recognised by geologists, and described as a "phosphate 

 paste" intermediate between the gault and lower green-sand. It is abotit lj feet 

 in thickness, and remarkable for its uniform continuity. It was doubtless this 

 same band which Mr. Payne discovered re-appearing on the south side of the North 

 Downs at Farnham, Steyning being situated on the north side of the South 

 Downs. 



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