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XXVI. — On the Value of the Microscope in the Determination of 

 Minute Structures of a Doubtful Nature, as exemplified in the 

 Identification of Human Skin attached many Centuries ago to 

 the Doors of Churches. By John Quekett, Esq., Assistant- 

 Conservator of the Museum of the Royal College of Surgeons 

 of England. 



(Read April 26, 1848). 



The vast number of highly interesting and valuable facts in natural 

 history and in philosophical anatomy which are daily being revealed 

 to us by the aid of the microscope, have quite established a new era 

 in these sciences. 



The links in the great chain of animated nature which heretofore 

 may have appeared wide and discordant, have, by an intimate know- 

 ledge of structural anatomy been brought more closely together. 

 Zoological classification, which in early times was based principally 

 upon certain distinctions and peculiarities in external form, now be- 

 gins to take a higher stand. 



In one order of animals the nervous system, in another the digestive 

 system, and in others the minute structure of the external or internal 

 skeleton, form at the present time the best grounds for classification. 

 Nature works with but few tools, but the material used, though often 

 of one and the same substance chemically, is nevertheless moulded 

 into an infinity of forms, and each form so perfectly characteristic of 

 the genus, or sometimes even of the species of animals, that a micro- 

 scopic examination only is required to identify them. 



The force of this argument may be well exemplified by the struc- 

 tures termed Hair or Wool. In any two animals, of totally different 

 genera, the hair when examined chemically may be in composition 

 identical, but when submitted to the microscopic test, may be found 

 so manifestly different that the unpractised eye can readily discrimi- 

 nate between them. No one, I am certain, is better aware of this than 

 our worthy President, who has paid particular attention to the struc- 

 ture of hairs in different classes of animals, and no one is more likely 



