112 OX PHOSPHATE NODULES. 



fowl. It was at that time used as a manure with great advantage on the 

 coast of Peru, where the soil i3 otherwise extremely sterile. 



The percentage of phosphate of lime in guano is about 29. Its first 

 trial in England (in Mr. Skirving's nursery at Liverpool, upon grass and 

 turnips) established its reputation as far superior to any known manure ; 

 the price, moreover, of its importation being only from 20s. to 25s. per 

 cwt. 



By the year 1844 the application of guano had become various and 

 abundant. But hitherto Liebig's speculations had not been realised in 

 England. It was in the year 1843 that Professor Henslowand his family 

 were staying for a few weeks at the pretty and retired village of Felix- 

 stow, on the Suffolk coast ; and, though at that time generally con- 

 demned as a watering-place, yet it is seated on one of the noblest bays 

 in England, with excellent and safe bathing, possessing a maritime Flora 

 of much interest, with a fine denudation of one of the most remarkable 

 of our British strata ; having, moreover, the alluvial soil filled with 

 fragments of Roman pottery, mixed with the well-preserved remains of 

 deer, oxen, and every description of animal, including snails (!), which 

 the Romans had fed on 1,400 years ago, intermixed with coins and other 

 objects of antiquarian curiosity. On the north of Felixstow high cliffs 

 face the sea, the lower and greater portion consisting of " London clay," 

 a blueish grey bed crumbling under exposure to the atmosphere, and 

 abounding in large septaria or nodular masses of stone, of about three 

 feet in diameter. Vast quantities of these are collected for the purpose 

 of making cement. A little flotilla of boats may often be seen a mile or 

 two out at sea dredging for them. 



Superimposing the London clay is the " red crag," so called from its 

 peculiar yellowish-red colour, due to the great prevalence ot oxide of 

 iron. It is for the most part a sandy bed, abounding in vast quantities of 

 rolled and water-worn organic remains. Numerous sharks' teeth, varying 

 in size from half an inch to four inches in length ; portions of whales' 

 bones, especially the ribs, and the petrous tympanic bone of the ear ;* 

 innumerable fragments of marine shells, together with layers of nodular 

 masses of indurated clay, the miscalled " coprolites," constitute the cha- 

 racteristic features of the red crag. These nodules appear to have 

 derived their origin from the London clay, in which many were found, 

 by the late Mr John Brown, of Stan way ; differing, however, from the 

 former, in the absence of the peculiar dark-brown colour on the exterior 

 surface, and from bright yellow being often disclosed in the interior by 

 fracture.f 



In consequence of the sea's encroachment at this point of the eastern 



* So abundant have these " whales' ears" subsequently proved, that the Pro- 

 fessor had at one time in his collection no less than 32 dozen ! A description of 

 them may be found in Owen's ' British Fossil Mammals.' 



+ Hence the names of "eggs" and "fruits," locally given to those of a some- 

 what roundish form. 



