194 Rev. J. B. Reade on Organic Remains 



accuracy is secured by the image of the objects having been 

 thrown on paper by means of a Camera eye-piece, and then 

 carefully traced. At the same time I cannot but observe that 

 a magnifying power of 1000 linear, together with Ross's fine 

 adjustment, gives a reality which no drawing can impart. We 

 can trace our way down the arms, and penetrate what, com- 

 paratively speaking, appears to be a vast sphere, since it is no 

 exaggeration to say that it would require nearly a thousand 

 million individuals to fill up the image thus presented to the 

 mind. 



As to the manipulation of the flint, in order to prepare it 

 for the stage of the microscope, the readiest method by far is 

 to break a large nodule in half, and from the flat faces to chip 

 off thin fragments, which may be attached by means of Canada 

 balsam to slips of glass of the usual form, and then coated on 

 their outer surface with hard spirit varnish. A hundred spe- 

 cimens maybe thus cut, mounted, and polished, without trouble 

 or expense, and in less time than an expert lapidary could pre- 

 pare a single slice with the diamond-mill and polishing tool. 



It is the received opinion among geologists, that the nature 

 of the strata of the chalk, and the organic remains which they 

 inclose, prove that the chalk was deposited in the tranquil 

 depths of an extensive and profound ocean. This conclusion 

 is rendered probable by the chambered Nautili and micro- 

 scopic Foraminifera of flint, and it will derive additional force 

 from a recent very interesting discovery of scales of fossil 

 fishes, of great variety of form and in a state of most delicate 

 preservation, throughout the entire series of the flint nodules 

 both of the chalk and gravel, from Gravesend to Rochester 

 ^nd Gillingham*. A few weeks ago a single scale was disco- 

 vered by Mr. Darker upon a fragment of flint which he had 

 selected for a supply of the Xanthidium, but as he was igno- 

 rant of its locality he made no further search for similar re- 

 mains : shortly afterwards a pebble was brought to me for my 

 usual mode of examination, and upon its surface, I acci- 

 dentally discovered the second scale, and had the advantage 

 of knowing that I could apply to an inexhaustible store. 



• The rolled flints of the Norfolk gravel-beds also abound with fossil 

 scales. 



