•THEAICRgSCOpP 



:ated 



Vol. XI. 



TRENTON, N. J., NOVEMBER, 1891. 



No. 11. 



ORIGIMAL 

 COAnVMICATIOMS 



MICROSCOPE OBJECTIVES. 



(read before the am. soc. of microscopists.) 

 prof. t. j. burrill, ph. d. 



I HAD the honor of presenting to this societj'^, at its last meet- 

 ing, a paper embodying my experience and opinions concern- 

 ing tlie microscope. I now wish to offer tlie results of personal 

 experience in the use of various objectives for microscopical 

 work, especially along the lines followed as a teacher and inves- 

 tigator of biological science. The task thus set before me is 

 more difficult than that of last year. Liitle niceties of difference 

 count much more in an objective than in the construction of a 

 stage, or rack and pinion adjustment; and though one may be 

 sure that his preference is not founded upon fancy, yet he may 

 find it hard to state in words upon just what special characteris- 

 tics he bases his choice. In the paper of last year the names of 

 makers were carefully excluded ; this time it is impossible to 

 get along without reference by name to the manufacturers of the 

 instruments cited. I heartily wish it could be avoided and 

 accomplish the purpose intended, for it is a source of embarrass^ 

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