PART I. 



CHAPTEE I. 

 THE MICROSCOPE-STAND. 



As one looks through the catalogues of the various dealers, 

 and notices the microscope-stands varying in price from 

 2 to 40, a feeling of bewilderment arises as to what is 

 essential and what can be dispensed with. We will, then, 

 examine the parts, describe their uses and advantages, and 

 state what is necessary for a beginner. 



Here let us advise intending purchasers not to buy a 

 microscope unless it bear the name of a manufacturer : a 

 good workman is never ashamed of his handiwork. There 

 are many very inferior instruments that look tempting, but 

 a practical acquaintance with them soon discovers their 

 weak points and inefficiency. Happening to attend the 

 conversazione of a well-known microscopical society, at 

 which there were exhibited over one hundred instruments, 

 it was surprising to note the many makeshifts of micro- 

 scopes belonging to some of the exhibitors and many of 

 them had probably cost a fair price, too. A manufacturer 

 once remarked to the writer that he was some time ago in 

 a provincial town, when an auctioneer asked him whether 

 he could make him up a job lot of microscopes for sale by 

 auction, as he was very successful in disposing of a certain 

 class of pictures in that way. The disgust of the scientific 

 workman can be better imagined than described. The 

 microscopes often seen in the novice's possession seem to be 



