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SUPPLEMENT 



How can animalcules so inconceivably minute 

 be congregated in such masses? What new 

 powers have been added to the microscope by 

 which it is enabled to develope these delicate 

 formations ? In reply to the latter question, 

 we simply state the fact, that recently a high 

 degree of defining and penetrating power has 

 been given to the microscope, for want of 

 which, at an earlier period, researches into the 

 minutice of nature were frequently inconclu- 

 sive anjideceptive. Deeper magnifiers than 

 any formerly known are now, also, brought 

 into effective use. The first inquiry, how 

 can these animalcules be collected in such 

 countless myriads of myriads ? will be satis- 

 factorily answered in the following extracts 

 from a most talented article in Chambers' 

 Edinburgh Journal. 



" The productions of the kindred zoophytes, 

 in the innumerable coral reefs and islands 

 which bestud the ocean, are truly wonderful ; 

 but not less astonishing certainly is it, that the 

 organic remains of these invisible atoms should 

 abound to such an extent, as actually, in the 

 language of Dr Ehrenberg,to swell in no small 

 measure the amount of the solid matter of 

 the crust of the globe. Many of these ani- 

 malcules are of a beautiful green colour. If 

 water, then, containing some of these, be taken 

 from a pool or marsh, and conveyed into a co- 

 vered vessel, a layer of fine powder, speedily 

 becoming a green crust, will ere long be found 

 on its surface, and more particularly near the 

 margin of the glass. This crust, at first a 

 bright green, gradually assumes a brown and 

 yellow hue. This constitutes the well known 

 Priestley matter of former days, which at one 

 time so much engaged the attention of philo- 

 sophers. It seems formed of the more solid 

 portions of these animalcules, which, in succes- 

 sive generations, have ceased to live." The 

 fecundity of these small animals is beyond all 

 conception : each individual produces a host; 

 and " generation succeeds to generation with 

 a rapidity which cannot be estimated, and 

 their remains thus accumulate in countless 

 myriads, and to a vast extent." The slimy 

 substance which not unfreqnently covers stag- 

 nant waters, and is sometimes spread over 

 wet and marshy soils, has been discovered to 

 consist of large masses of animalcules in thin 

 layers. " When we are thus informed of lay- 

 ers of dead infusoria formed on common 

 marshes, or in ditches, we are in some mea- 

 sure prepared to understand how the same 

 substances may have formed great layers or 

 strata, taking their place amongst the other 

 rocks which fall under the attention of the ge- 

 ologist. The fact, however it may be received, 

 is so. Vast layers of rock, at or near the sur- 

 face of the earth, and many feet in thickness, 

 have been discovered in various parts of the 



world, which the microscope has found to be 

 composed solely of the shields or hard parts of 

 Infusoria ; these remains of Infusoria having, 

 of course, been deposited from great bodies of 

 water which formerly overspread the place. 

 Dr Ehrenberg has actually shown, by experi- 

 ment in the royal deer park at Berlin, how such 

 rocks may be formed by means of the Infus- 

 ory tribes ; and the only difference between 

 the crust formed in experiments like his, and 

 a layer of rock several feet thick, and of 

 large extent, is in the scale on which the 

 phenomenon takes place. In the one case 

 we have a natural operation on a large 

 scale, and in the other an artificial operation 

 on a small one. All the other features of 

 the process must be considered as identical." 

 The writer from whom we have been quoting, 

 dismisses his subject with these apposite re- 

 marks : " No doubt the abundant vegetation 

 of the elder world, to which we are also in- 

 debted for our beds of coal, had something to 

 do with the production of these vast quantities 

 of animalcules, which never fail to be found 

 where the least amount of dead vegetable mat- 

 ter has been allowed to rest in still water. 

 Extensive seas of fresh water, commingled 

 with decaying forests, or which had passed 

 over such, would be the birth place of our fossil 

 Infusoria, the remains of which, as generation 

 after generation perished, would sink in an im- 

 palpable powder to the bottom . and there in time 

 be accumulated in the form of a layer of rock." 

 The fossil remains of vegetables present 

 most interesting phenomena to the geologist; 

 these have been already referred to and illus- 

 trated in the course of the work, and in this 

 place we have only to notice that the micro- 

 scope affords considerable aid in the develop- 

 ment of this class of objects, particularly the 

 fossil woods, specimens of which can now be 

 procured cut so extremely thin as to admit of 

 their being viewed by transmitted light, by 

 which means all their peculiarities of struc- 

 ture can be readily ascertained. We shall 

 lay before the reader Mr Pritchard's eloquent 

 and philosophical remarks on this subject : 

 " To the botanist the aid of the microscope is 

 indispensable. In the investigation of our 

 fossil-flora, what does it not exhibit to us ! 

 How beautiful and delicate is the structure 

 of the envelope of some of the fossil-fruits; 

 those, for instance of our London clay, 

 when viewed under this instrument! And 

 how important is it, that, by its assistance, 

 we can determine with accuracy the natural 

 orders, genera, and sometimes the very species 

 of the trees and plants of former epochs ! 

 How, beyond all question, is now demonstrated 

 Ihe vegetable origin of our coal ! Preserved 

 within a bituminous lump of coal, which has 

 been deposited for thousands of years deep in 



