65 



On the " Illuminator Hand Microscope." 



By Dr. Guy, F.R.S. 



Communicated hy Mr. James How. 



In submitting to the Quekett Club, at the request of Mr. James 

 How, some account of the instrument to which I have given the 

 name of the ^^Illuminator Hand Microscope,''' I begin by pointing 

 out what I deem new in the parts of the instrument, and in the 

 instrument as a whole. 



There is something of novelty in the substitutioji of what may 

 be fitly termed a Glass Lieberkuhn for a metallic one ; but it is, I 

 believe, a quite new expedient to make the Lieberkiihn a fixed part 

 of the microscope, and in such sort that it may be a matter of 

 perfect indifference whether the object under examination is trans- 

 parent or opaque. 



Again, it is no new thing in my own practice to mount micros- 

 copic objects on flat disks of crown glass, and so place them in a 

 hand microscope that they may be viewed by any number of per- 

 sons in succession, without possibility of disturbance. But objects 

 so mounted on disks are new as articles offered for sale to the 

 public. 



Then, as to the instrument considered as a whole : — A hand 

 microscope is not new in this year 1872, though I believe it to have 

 been a novelty when I first used it for class purposes in the year 

 1859, now 13 years ago. And you all know that my esteemed 

 colleague. Dr. Beale, has more recently made good use of the form 

 of the hand, or class, microscope adapted to evening use by a 

 lamp mounted on the same stand as the microscope itself. 



A hand microscope, then, is no novelty. But a microscope that 

 can be used in the same way, and with the same facility as an 

 opera-glass or field-telescope, which does not require to be pulled 

 to pieces and set up afresh each time it is used (as is the case with 

 so many cheap microscopes), which deals exactly in the same way 



JouRN. Q. M. C. No. 20. F 



