Ill 



PHOSPHATE NODULES.* 



BY THE REV. GEORGE HENSLOW. 



Like all other sciences, that of agriculture has of late years made 

 rapid strides in advancement, and one of the most important points that 

 has engaged the attention of scientific agriculturists is the employment 

 of manures specially adapted to particular crops ; amongst which are 

 those derived from artificial and mineral sources. It is our purpose to 

 narrate the discovery and introduction of the use of "phosphate 

 nodules," or " coprolites," (as they are generally but wrongly called), 

 as a manure more particularly requisite for root crops. Although thou- 

 sands of tons are annuallyt prepared from different localities, but few of 

 our farmers, who derive vast benefit from them, have any idea that my 

 father, the late Professor Henslow, of- Cambridge, merited their thanks. 



In the year 1839 Professor Liebig first suggested the use of super- 

 phosphate of lime from bones for agricultural purposes.J 



Again, in 1843, he strongly advocated the more general use of phos- 

 phates. " A field," he says, " in which phosphate of lime, or the alka- 

 line phosphates, form no part of the soil, is totally incapable of pro- 

 ducing grain, peas, or beans.' ' § 



Again, he declares that "if a rich and cheap source of phosphate of 

 lime were open to England, there can be no question that the importa- 

 tion of foreign corn might be altogether dispensed with after a short 

 time." He here (p. 176) speaks in allusion to the coprolites|| discovered 

 by Dr. Buckland in 1842. The enthusiastic chemist concludes his letters 

 with the following remarks : — " What a curious and interesting subject 

 for contemplation ! In the remains of an extinct animal world, England 

 is to find the means of increasing her wealth in agricultural produce, as 

 she has already found the great support of her manufacturing industry 

 in the remains of a vegetable world. May this expectation be realised, 

 and may her excellent population be thus redeemed from poverty and 

 misery !" 



Previous to Dr. Buckland' s discovery, guano had begun to be imported 

 (1841) from islands in the South Seas, where it forms a stratum many 

 feet thick, T being the accumulation for ages of the excrement of many sea- 



* From the 'Leisure Horn'.' 



f An estimate, taken by Mr. C. W. Johnson, of the annual consumption of 

 superphosphate of lime made from "nodules," miscalled "coprolites," gives 

 72,000 tons, at an expenditure of £360,000 ('Midland Counties Herald,' Feb 20, 

 1862). 



J ' Organic Chemistry of Agriculture,' p. 184. Taylor and Walton. 1840. 



§ ' Familiar Letters on Chemistry.' Taylor and Walton. 1843. 



|| Fossil excrements and bones, etc., of saurians, in the lias near Clifton, con- 

 taining about 18 per cent, of phosphate of lime. 



TJ The author has in his collection a small penguin that was embedded in the 

 guano, possibly above 3,000 years ago ! 



