Fossil Bones and Pseudo-Coprolites of the Crag. 105 



conversion of carbonate into phosphate of lime, took place, and they 

 suppose that it was in this way that the phosphorites were formed 

 in all the strata of the crag. The nodules having been imbued 

 with phosphoric matter " from their matrix in the London clay," 

 writes Dr. Buckland, they were dislodged by the waters of the 

 seas of the first period, and accumulated by myriads at the bottom 

 of those shallow seas where is now the coast of Suffolk. Here 

 they were long rolled together with the bones of large mammalia 

 and fishes, and with the shells of molluscous creatures that lived in 

 shells. From the bottom of this sea they have been raised to form 

 the dry lands along the shores of Suffolk, whence they are now ex- 

 tracted as articles of commercial value and ground to powder in 

 the mills of Mr. Lawes, at Deptford, to supply our farms with 

 a valuable substitute for guano, under the accepted name of 

 coprolite manure." 



Dr. Buckland has even proposed to take advantage of this 

 curious property which is possessed by calcareous matter, and 

 render it of service in the production of a similar manure from 

 the sewage and sewerage-water of large cities. He says he has no 

 doubt that the addition of carbonic acid to sewage, and protoxide 

 of iron and salt, with a moderate heat, would induce conditions 

 approaching to those under which analogous compounds were 

 formed from putrescent animal and vegetable matter in ancient 

 deposits, both under salt and fresh water, throughout all geolo- 

 gical time. 



The only serious objection to this schemelies in the longperiod 

 of time that would be required in order to effect the desired con- 

 version. 



Thornton J. Herapath, 

 Assistant Lecturer on Practical Chemistry 

 at the Bristol School of Medicine. 



Mansion-House^ Old Park, Bristol, 

 July 17, 1851. 



V. — Essay on the Cultivation of Oats. By John Haxtox. 

 Prize Essay. 



The cultivation of oats is very general throughout the whole of 

 Scotland, Ireland, and the North and West of England. In the 

 two former countries it forms a prominent feature in nearly every 

 rotation of crops, and although less so in the districts of England 

 referred to, the practice is sufficiently common to warrant us in 

 classifying them along with Scotland and Ireland, as possessing a 

 soil and climate adapted to the special requirements of the oat 



