PREFACE. 



AT the period of the publication of the first edition 

 of this work in 1829, microscopes on the new prin- 

 ciple had only just sprung into being, and some 

 apology for a treatise upon an instrument which 

 then apparently had little but novelty to recommend 

 it, might have been thought requisite; since that 

 time, however, its application to the sciences, and 

 the pleasure derivable from it as a source of amuse- 

 ment, have rendered this unnecessary. 



It will be found that the present arrangement 

 of the papers is different to what it was in the first 

 edition, that having been suited to their being pub- 

 lished in numbers, which occasion being done away 

 with, Dr. Goring' s are now placed together, and 

 with them the description of his instrument. 



In the first chapter of this volume the reader is 



