THE ARCTIC ANIMALCULE. 287 



Microscope (in Regent Street, Piccadilly), and several 

 others of a similar nature exhibiting in London. Mr. John 

 Varley, Mr. Bauer (of Kew), and Mr. George Francis (of 

 Berwick Street, London), have constructed powerful instru- 

 ments of this nature. 



The contemplation of animalculae has made the idea of 

 infinitely small bodies extremely familiar to us. A mite 

 was by the ancients considered as the smallest animal in 

 existence ; but naturalists are not now surprised to be told 

 of animals tzcenty-seven millions of times smaller than a mite. 



Minute animals are proportionally much stronger, more 

 active and vivacious than large ones. The spring of a flea 

 in its leap, how vastly does it outstrip any thing the greater 

 animals are capable of! A mite, how vastly faster does it 

 run than a race-horse ! Mons. de LTsle has given the com- 

 putation of the velocity of a little creature scarcely visible 

 by its smallness, which he found to run three inches in half 

 a second. Now, supposing its feet to be, the fifteenth part of 

 a line, it must make five hundred steps in the space of three 

 inches ; that is, it must shift its legs five hundred times in a 

 second, or in the ordinary pulsations of an artery.* A 

 similar fact is mentioned by that delightful author and my 

 kind friend, Mr. Sharon Turner, in his invaluable work ;f one 

 which has afforded me the greatest pleasure in its perusal. 



T,he excessive minuteness of microscopical animalculae 

 conceals them from the human eye. One of the wonders 

 of modern philosophy is the invention of the means to pro- 

 duce instruments, whereby the perception of these creatures 

 may be brought under the cognizance of our senses: an 

 object of a thousand times too little to be able to affect us. 

 Yet we have extended our views over animals to whom 

 these would be mountains. In reality, most of our micro- 

 scopical animalculae are of so small a magnitude, that through 



* Hist. Acad. 1711, p. 23. 



t The Sacred History of the World, as displayed in the Creation, and 

 subsequent Svents to the Deluge, attempted to be philosophically con- 

 sidered in a Series of Letters to a Son, by Sharon Turner, F. R. S. Fourth 

 Edition. Longman and Co. 



