EYES AND SCALES OF FISHES. 381 



and immediately corked up or sealed over, yet are found, after 

 some hours or days, to be replete with myriads of animalcu-* 

 les ; but I believe no experiment goes to shew, that any ani^ 

 malcule could itself withstand such a degree of heat. In these 

 obscure departments of nature, however, there is no reasoning 

 with certainty from mere analogy. Before Tremrley's disco- 

 very of the nature of the polypus, it could scarcely have been 

 credited, that there existed any animal which might be multi- 

 plied almost ad infinitum, by cutting it into pieces ; and there 

 are many other phasnomena in the animal kingdom, which 

 stand as it were insulated and independent of the laws which 

 govern the chain of animation to which they belong. Thus 

 vinegar proves an instantaneous poison to all animalcules found 

 in other fluids, yet the vibrio aceti is found in vinegar, and in 

 it alone, Some animalcules, after being dried up for years, as 

 the eels in blighted wheat, revive upon the application of moi- 

 sture ; and the insect named the puceron, or vine-fretter (as 

 discovered by Bonnet), contrary to all analogy, propagates 

 without sexual intercourse down to the ninth generation. 

 From these, and many other similar occurrences, it must be 

 evident, that analogy, in our researches into the lowest classes 

 of animal life, must be a fallacious guide. Perhaps, therefore, 

 without too far transgressing the bounds of probability, we 

 may admit the possibility of the existence of a being possessed 

 of animation, and yet capable of resisting a heat as high as 

 212°. 



Second, It appears very absurd to suppose, that any organ of 

 a living body should be composed of a congeries of other mi- 

 nute animated beings or animalcules. 



But, at one time, it would perhaps have seemed nearly as 

 great an absurdity, to suppose that such beings existed in any 

 of the secretions; yet the discovery of Lieuwenhoeck, and the 



Vol. VIL P. IL 3 C observations 



